How The Simpsons - Tapped Out is making money

Recent news about EA’s new The Simpsons – Tapped Out game shows that tablet-optimized social game earned more than $23 million during Q3 2012.

So what makes Tapped Out so engaging gaming experience that it a) retains users and b) monetizes them so that it makes so big numbers for EA? Let’s check it out!

The back-story of the game is that Homer accidentally was so engaged into playing the tablet game of Tapped Out that he forgot to watch out nuclear plant meters which of course caused plant to explode and blow away whole Springfield. Player’s goal is to help Homer to rebuild Springfield and invite the old inhabitants back to Springfield.

Look and feel of the game is genuine Simpson-style. Game uses same graphical style, character voices and the humor which people has used to experience when watching The Simpsons on TV. The controls of game itself are well optimized for touch devices; touch controls are quick and accurate and user interface logic suits well for mobile devices with large screens.

Game has two in-game currencies, namely the usual soft currency which in this case is cash and the hard currency which is branded in the Simpson-style as donuts. Soft currency is the primary currency of the game and player can buy most of the items with soft currency except some special buildings and items. Player can earn only small amounts of hard currency in the game by leveling up or inviting friends. Hard currency is mainly used for speeding up and to buy some premium items.

Core Loop

The game features one dimensional core loop. The loop consists of building more building to player’s own town and collecting most well-known characters of the franchise by that. Constructing the buildings take time and money, but earns experience to the player. Collecting different characters compels to humans primal “hunt & gather” instinct which is why these kinds of loops are very successful in games.

The more buildings player can construct to town, the more taxes (cash + XP) he can collect from them. Different buildings have different waiting times which player has to wait (or pay) in order to collect taxes. Also, different buildings have different amounts of taxes which can be collected from them.

Another element to the core loop is managing the life of the inhabitants. Every character in the town has his / hers own little “yellowish” chores to do in the game. In general the chores  do not affect the appearance or core-loop of the game, but are more like busywork; keeping players busy and adding another monetization layer to the game but at the same time, creating emotional bonds to the characters and creating feeling of “my town”. In my opinion busy-work don't add the value of the game but still they are quite widely used throughout social games.

Lisa's chore-list = busywork

In addition to basic core loop, the game features also mechanic called “Conform-o-meter”. Conform-o-meter measures how well player can grow town so that special meters fill up. These meters include e.g. Consumerism, Vanity and Socialism among others and they measure how well the inhabitants can go to shopping, how well decorated the town is and how well player has made friends and visited their towns. Game rewards the player for reaching the meters with added money and XP.

Visit my town! a.k.a the Virality

Some would want to know how the social aspects show up in the game because – after all – this is social game. So let’s dive and see how social this game truly is.

Game includes popular social hooks / invites. This means that player can invite friends to join as his neighbors by using channels such as EA’s own Origin -network, Facebook, Google Mail or iOS device’s contacts. Everyone has to join to Origin in order to use social features, but luckily the registration process in-game is fairly easy to do.

View from the neighbourhood

Tapped Out’s only social feature inside the game is the ability to visit player’s friends’ towns. In current version of Tapped Out, players visit their friends’ towns in order to send Valentine’s Day cards to the friends and thus helping friends and themselves. Cards are sent by clicking (maximum three times a day per town) the buildings in the town. By clicking buildings players gain more experience, cash and hearts for themselves and for their friends.  Hearts are special kind of in-game currency which players can use to purchase special Valentine’s Day items (limited time around Valentine’s Day). Sending Valentine’s Day cards to friends is easy and rewarding way to integrate the social aspect in the game since it compels users to invite their friends to the game as well.

Sadly this is as far as the game gets in the social mechanics. It’s sad because social mechanic doesn't really affect any other part of the game than the player receiving more experience and in-game currency. Secondly the only feature which the game includes in terms of social aspects is exactly the same thing what e.g.  Zynga did back in the days with their first Facebook games including FarmVille.

It would have not taken much effort to introduce little bit evolved social mechanic to the game where users could help their friends by integrating the help features more into the core loop of the game. 

The Monetization

It’s interesting to see the level of of the cheapest currency-pack goes up and up when the platforms and games evolve. Before iPhone was launched back in the days, Travian, Farmville and bunch of other social games started at 0,49€ currency packs. Now the usual starting price seems to be something like 4 to 5 euros.

In Tapped Out, the minimum price for currency pack is 1,79€ which is mystery for me why that is so low. 

In Tapped Out, player pays for speeding up the progress (constructions and chores) of the game as well as by paying from some special items and buildings. And there’s a LOT of items you can buy only with hard currency. From most expensive item the player has to pay 250 donuts and all the premium stuff together is worth of 2743 donuts. With a maximum one-time IAP of 2400 donuts wih 89,99€

Because the game is so well optimized for DAU (as I explain later), the game could monetize better the players who doesn't want to wait. Now all the waiting is tied to the max 24-hour cycle which decreases the conversion rate from players to payers. 

Engagement

Biggest element for high engagement and thus retention rates are well balanced core-loop and compelling, tablet-optimized gameplay. Core loop is designed to keep DAU high because every task of the characters, building & tax income times of the buildings doesn’t exceed 24h. In addition, the way the rewards of the tasks of the characters, finished buildings and send / received Valentine’s Day cards are showed to the player is very compelling. It’s very rewarding to come back in the next day and tap & see how the rewards fly to oneself on the screen of iPad.

Scratch-R tickets. Can you scratch the itch?

In addition to core loop, Tapped Out includes basic engagement features. First, there are the daily rewards which reward players with money for coming back daily. The cash rewards increases daily for a week and in the last day there is special lottery prize available for player.  After one week the reward loops starts again from the beginning.

Another engagement feature is Daily “Scratch-R” scratching tickets which players can buy with soft currency once per day and if they want buy more, they have to pay hard currency. These kinds of luck-elements are especially popular in Asian countries (according author’s own references) and may monetize very well there.

1st gen social game in 3rd gen platform

I think that Tapped Out is the iteration of 1^st gen social game which means that the social aspects of the game doesn't really add value to the core game mechanics but rather just rewards  the player for visiting their friends town with in-game currency.

I think the game has very good retention rates and it monetizes mainly from players who would like to buy the premium stuff or the Asian players for scratching those tickets. It could do better if the game’s progression would be designed to slow down (= longer waiting) after some while from beginning of the game to create primed to spend moments.

The retention rates could be quite easily pulled even higher by enabling players to upgrade their buildings or create ad-hoc relationships between the character of their town. Now the game doesn't give any visual feedback on the progression other than giving and showing piles of in-game currency to players which they can buy more buildings.

Apart from the monetization and retention – or in conjunction with them – the game could do a hell of a lot better with integrating social aspects into the game. The first thing would have been to think easy and creative ways to collaborate and integrate fabulous Simpson characters into it. What could have been funnier than to find and catch (read: tap) “the lost cats of Crazy Cat Lady” and send them back to a friend from whose Crazy Cat’s are they? Or how about enabling players to create their own baseball league championships after they have managed to build the stadium and invite their friends to take part in it? There’s a tons of more good and easily implementable ideas from the franchise which could have been integrated into the game to create more social game.

Apart from the social aspects, I think EA is quite pleased with the numbers what the game has done but I sincerely hope that EA has some ideas waiting to get implemented so that the players would get more value from this social game. Now it just seems that EA has went easy but hollow way of creating social game by copying the basic design principles from early Zynga games which creates good numbers for EA due to high discoverability of The Simpsons franchise, heavy user acquisitions and 24h optimized (but still hollow) progression loop. Simply put it's fist gen social game on a third gen platform.

Four common practices for increasing engagement in f2p mobile games

I thought I would share some effective practices for increasing engagement in f2p mobile games which are not tightly coupled to any particular type of game. With goal of reducing misunderstandings, these of course are not effective if the itself game is bad.

Some of them are very  generally used in games, but not very well implemented in some of them. Here, I will depict my my own thoughts what you should think about before hurrying up with the actual implementation.

Facebook / Social integration

All the time Facebook brings more and more valuable services to mobile game developers for free which greatly increase the engagement of players when they can play against and with each other, compete, brag and send gifts and also compare the progress of their game play to each other. Here's some best practices for integrating Facebook to your game.

Allow players to see each others' progress in a same view where they see their own - Candy Crush Saga does this exceptionally well with its world map and progression line where users can see their own and friends' progress in one shot.

Your own progress and your friends' progress in a one view

Boom Beach allows players to see each others in the map view of the game, but doesn't make any effort to enable players show off with their progression. Small changes either to icons of the players and/or to pictures of bases could add significant ego-boost value to user.

If possible, allow players to challenge each other - Highly effective way of increasing engagement. When you - as a player - has been challenged by other human being, or even better, someone you know, it creates different kind of motivation to show your superiority to other player. If this methods can coupled with push notifications, it's best way to engage players to your game.

Daily gifts

Daily gift is a common way for most game developers to engage those users who come back to game. However, thought should be exercised when designing the visual looks, user experience and user interaction of the daily gift use case. Below my five cent's on daily gifts.

Daily gift  in Diamond Dash by Wooga is well thought. The user experience is rich, the steps to getting the gift from opening the game is low and the more days the player returns to game in a row, the better the prizes are.

Reward players - Don't be a jack-ass and try to deceive players by giving something which is no use for players - players will notice it. On the other hand,  reward the players with usable items and also make the interaction of getting the gift rich.

Don't dilute your game economy - You should also make a living with your game, don't give excessive amount of premium currency for your free-to-play game.

Add element of luck to it - Luck is an important element of daily lives in the Asian cultures and there are huge amount of people in the western countries as well who like to gamble a bit. Don't miss your luck and implement the luck element to your daily gift procedure.

Motivate players to come back, every day - By rewarding players with better rewards when they come back to your game 7 days in a row if very effective strategy for increasing engagement. It's your own loyal customer program!

Think about user experience - This is something which is very hard for most developers to effectively understand. Supercell does this well in Hay Day in one use case where players can search and tap those special mystery boxes and find some items or money from those. Boxes and the way of getting items from them fits perfectly to the game and to the general user interaction scheme in it.

As a developer, you should reduce the number of steps which are required from the player to get the daily gift, but also the daily gift mechanic should fit to the style of your game and to general interaction scheme so that the players can use it.

Achievements / Missions

Achievements increases engagement for the achievers. The people who always wanted to have a-grades from every test and project. Achievements should be designed in a way that during the first seven days in the game, players could achieve at least one achievement per day to keep him engaged. After the first week, the pace could decrease to one achievement per two days. If you can reward player for getting achievement it naturally increases the engagement.

Also think about rewarding players with permanent decorative items after they have completed the mission/quest/achievement so that they can show off to other players in the game. 

Notifications

Notifications are very commonly used in mobile games because they are easy to implement and (seemingly) are tremendously effective in engaging users.

But looks might be deceiving. Even if the notifications could (remember that user can always opt out of having notifications) appear to user's device's screen it's too usual that the content in the notifications are too trivial, irrelevant or they appear too often so that the user either doesn't care or gets irritated and decides either to turn off notifications or uninstall the game.

Here are some tips for fine-tuning the notifications.

Stay relevant - Think about the player and things which might actually help her to be better in the game and not just throw out a bunch of pre-scheduled notifications reminding player to come back to game. Think about triggering notifications to events in the game which could help the player in the game. For example, notifying player when the castle has been built or when energy has been refilled or when other player has attacked to your village.

Stay short - the more shorter way you can express your message, the better and more understandable it is. Period. (Also, Apple limits push notifications' payload to 256 bytes, damn.)

Be surprising - I still remember how dazzled I was when I was heard Homer Simpson's voice from my iPad when Simpsons - Tapped Out was reminding me that taxes of the residents in my Springfield were due. Damn! That was surprising!

Let players decide - In addition to allow users to turn off notifications it's a good practise to allow user decide what kinds of notifications (local, push, voice, text etc.) they want to receive and how often. If they truly are engaged to your game, they will use it.

So here's short list of commonly used practices to increasing engagement in mobile games with additional hints from me.

But as I'm always hungry to learn more and going deeper I want to know what kinds of strategies for player engagement have you been using or seeing in games? Please share them in the comments!

Supecell's next game Boom Beach analyzed

As most eager fans have already seen, Supercell has been testing their next mobile game Supercell in Canadian App Store. Boom Beach was launched in Canada in 8th of November 2013 and it still is "under testing" in Canada.

Let's dig through the main game pillars of the game, analyze how it differs from Clash of Clans in terms of gameplay, monetization and engagement aspects and finally, let's discuss how these changes might affect the core audience of the game.

Gameplay

Baseview from Boom Beach

For any of you who don't know what Boom Beach is, it is a strategy management game - similar to Clash of Clans. The main goal of the game is to develop one's own military base and conquer surrounding islands from AI-players and other human players by accessing the map view from in-game ui.

Obviously, the first main difference is that instead of medieval-fantasy theme what is used in Clash of Clans, the theme is now military. Basic troops consists of Riflemen, Heavys, and Zookas which all have their own strengths and weaknesses and basic buildings are military bases, residence buildings, gold storages, sniper towers, mortars and machine guns, to name a few.

Second distinct difference is that battles against AI-controlled enemies and human opponents can be accessed from one single map view.  How much world is uncovered from fog of war depends on the level of the Radar building and the urge of the player to spend gold to unlock areas from fog of war (unlocking areas costs gold, you know). 

Third big difference in the gameplay is that controlling of troops in the battle is a little bit more direct now. In Boom Beach player can control the target position of all the units in the battle by placing a flare in to the position where he wants the troops to go. But the tricky part is that the flares last only a certain amount of time and when they end, troops will start to attack to the nearest possible building from their position. So if the target position of the flare is too far away from the troops, they will never make it so far and might disrupt the whole attack plan of the player.

Fourth big difference in the battle mode of Boom Beach compare to Clash of Clans is the introduction of energy points and consumables to battles. Here's how they work: first, the base amount of energy points the player has is dictated by the level of the gunboat - the better the level the more energy points. Secondly, players can collect energy points during battles by destroying enemy buildings. Thirdly, player can use these energy points to use consumables such as flares, artillery, medkits and shock bombs which could have a big impact to the battle if used wisely.

And finally, the fifth big difference in the battles in Boom Beach is that the Headquarters acts as "all or nothing" type of building which means that if enemy can destroy the Headquarters, the battle is lost. Also, the health level of Headquarters is an effect of health level other buildings in the village. This means that if enemy can destroy the gold storage of your camp, the health of Headquarters decreases a bit. However, this doesn't mean that by destroying all other buildings in the camp, the result would be destroyed Headquarters.

In my opinion, with these design decisions, Supercell has created a game which is more "core" than it's previous game Clash of Clans mainly because of the depth of the battles. At least for me, there are far more variables to consider when planning the attack against other players and maybe that's why Supercell hasn't limited the amount of time the player can scout camps of enemy players. Also, fewer unit amounts and more direct controlling of the troops during battles creates more engaging battle gameplay experiences for the players.

Monetization

In terms of monetization there are quite a few elements to inspect to really get a grip on monetization aspect of the game

Virtual Currencies and Resources

First, let's go through types and amount of virtual currencies and resources in Boom Beach. There are three different types of virtual currencies in Boom Beach: Gold, Wood, Stone, Iron and one premium currency Diamonds. 

Gold is produced by the residence buildings; the more the player has these and the higher level they are, the more they produce gold in an hour. 

Wood is produced by Sawmill to which the same rules apply - the higher the level, the more it comes.

Stone is produced by the Quarry.

In addition to these basic resource production building which are directly accessed by the player, considerable amount of gold, wood and stone comes from the resource bases and which are conquerable by the human opponents in the game. Player can also gain these resource by winning battles in the game.

Gold is mainly used to train more units, to clear more area in the map, to fight battles and to research better types of power-ups from the Combat Academy. These are all "gold only" types of productions. Wood and stone are mainly used to construct and upgrade buildings and gunboat in the home base. 

From my gameplay experience it seems that stone is the most rare and sought after resource at least to player HQ level 7 (I have no experience from iron yet) . Also, the need for the "next-available-to-be-produced resource" starts before the resource production building is available for construction. For these cases, the only possible way to get these resources are by winning battles which increases the engagement of the game in these occasions.

Premium currency is used to speed up the training of units and to construction or upgrading of buildings so there are no special building types or items (at least not yet).

Builders

One of the most striking differences between the two games and clear differentiation from other mobile strategy management games is the absence of any type of builders in the game. There are no builder's hut or carpenter's hut or any other conveniently named item which they player could purchase from the building menu with premium currency. 

In-App Purchases

Premium currency diamonds is possible to buy with real money and they come in packs. The price points for different packs are 

4,99USD/4,49€ (500 diamonds), 

9,99USD/8,99€ (1200 diamonds), 

19,99USD/17,99€ (2500 diamonds), 

49,99USD/44,99€ (6500 diamonds) and

99,99USD/89,99€ (14 000 diamonds).

The price points of premium currency packs and the amount of premium currency in them are exactly the same than in Clash of Clans.

Progression speed

When I refer to progression speed within a f2p game I mean the pace of new content which is available for player whether it is through levelling up their experience level or upgrading the town hall, headquarters or by any other means. From developer's perspective this also means that how fast the content is being consumed.

In general, progression speed in Boom Beach is faster than in Clash of Clans. I have played Boom Beach irregularly now for about two months and my Headquarters is already in level seven, in the same level than my Clash of Clan's Town Hall. 

In my opinion, the biggest motivation for player's to spend premium currency is speeding up the training of troops. That's because there's not so much premium items to be purchased and because the core-loop with social aspects creates so strong motivation to engage to battles that players just don't want to sit and wait for their troops to be trained.

Retention, Engagement, Social

Like it has been discussed by fellow developers elsewhere, retention is number one metric for the success of free-to-play game because, in essence, they tell how good the game is. Also, every time publisher can increase retention percent, the chance to get more revenue from the user-base increases as well. 

Core-loop of the game affects partly to the success of the game and to retention percent of the user within it. I comprehend that well-balanced core-loop is one part of good retention and the other one are the social mechanics and their implementation in the game.

In Boom Beach, the core-loop is downrightly similar to that of Clash of Clans: player can collect resources, construct buildings, train troops and engage to battles. As discussed, there are big differences within that loop, but the basic building blocks of loop are the same.

Player can access both battles, against AI-controlled enemies and PvP fights from the same map view.

What comes to social mechanics of Boom Beach, there are no clans, no troop donations and no top lists. First, this might seem as a big impediment until the player understand how the dynamics of resource production, battles and building & training work.

First important thing to understand of the dynamics is that bases which player has captured do not last forever in his possession. They can be conquered by the AI-controlled Blackguard or by fellow players who are playing the game. And then you - as a player -  have to conquer them back if you do not want to lose your bases or your medals. This same loop goes on the rest of the game and it's the core mechanic in the game which drives up engagement rates, since if player wants to keep up the control of the bases, he has to engage to battles daily.

Second thing - which mostly affects to retention rates - is the introduction of fellow players within the game. Very early in the game play, player stars to notice that there aren't only the AI-controlled Blackguard bases in the map, but also bases controlled by other players. Although Supercell could a lot more in terms of visualizing the progression level of players in the map (currently only thing which visualizes the level of the player is number which is located besides the base icon), fighting against other players and conquering their bases is very motivating force to develop one's own base and troops. This is because the introduction of other players happens in the context and view of the game and the core loop and the actual event is important part of the core gameplay.

Summary

At least during testing phase still and at first glance, Boom Beach might seem as a stripped-down version of Clash of Clans but I think Supercell is doing the right thing because of following things:

1) The game  is still in soft launch period meaning that only the core of the product is released and new stuff is being added all the time. Who knows what they have planned for the global release?

2) The game is more "core" than Clash of Clans due to more direct controls and in general, the player has more influence to events and the end results of the battle. Being more core is also a valid thing to do in terms of platform mature and guiding the existing player-base from Clash of Clans to Boom Beach. 

3) Improving things here and there based on the feedback of the players. Supercell has the player base already which are accustomed to play "mid-core" strategy management games and Supercell has gathered vast amount of feedback from them which they can and apparently utilize in Boom Beach. Win-win situation for both.

That being said, it might be that Boom Beach will never see a global day-light, if the numbers don't count up in the end of the soft launch period. Can't wait to see how it all turns out!

Modern War Dissected

Modern War by Funzio (acquired by GREE) was first published back in November 2011 and has ever since floated between 57th and 1st in overall category for iPad in US grossing ranks and between 358th and 1st for iPhone in US grossing ranks, according to App Annie.

Here's my analysis and explanation why Modern War has been able to stick in the top grossing list for so long.

Core Loop

The core loop of Modern War is quite typical two-fold loop for modern casual / mid-core social mobile games. The core loop consists of building and upgrading of player's home base and  battling against NPC enemies or against other players in the game. Despite the overarching core loop being quite traditional, there is some special ingredients in the loop which makes this game interesting.

Battling - mix of energy mechanics and consumable items

Here's where the game gets interesting. There is the basic energy mechanic in the game which restricts the amount of possible actions in given time (called in the game: "energy"), but in order to attack against other human player in the game, the player needs second type of energy mechanic called "stamina". Both resources have their max cap which the player can increase with skill points when leveling up.

Dividing energy mechanics to two types of mechanics, the game limits the amount of actions the player can do against other players which increases the motivation of spending some dimes and also decreases the back-end costs (slightly, but still...).

In addition of energy resources, player needs different kinds of units in order to defend from or attack against to enemies, but unfortunately it is not very clear to player is there any effect on having these units in any case. I mean that the player can't see the units at his home base and neither he can select which kind of unit to use when he starts to attack to enemy base, but still the troops are one primary ingredient in the mechanics of the game.

If successful, the player will get experience points, cash and from time to time some troops for his use. In any case he or she will have to use some energy or stamina and cash to battle against the enemies.

Building and upgrading the home base

In order to unlock different kinds of troops, accomplish some missions and collect more cash, the player needs to build and upgrade his base. 

Player has to build different kinds of buildings in his base in order to fully leverage all troops which are available in the game. There are money buildings, unit buildings and defense buildings in the game, each of one helping with given type of objective in the game.  Unfortunately, the effect of each building is not very clearly visible in the game, other than in the store where the building is selected. Let me make this very clear and give an example; if I, as a player, want to increase the defenses of my base, I would of course build defense building. I would go to in-game store, select "defense buildings" and then select the appropriate building - in this case a guard tower. I see that it's defense points are 2 and range 8 and that it costs 5000 cash. But after I place it to base, I have no way of seeing how exactly does it affect my defenses and does the position of building have any more effect to defenses of my base. This is very clear in e.g. Clash of Clans and I reason that is one primary reason for it's success; the decisions what the player makes, are very clearly visible during the whole gameplay which is not the in Modern War.

Building and upgrading building in the base has also other implications; it increases the money which the player can earn from the money buildings (e.g. supply depot & armory).

Engagement

According to some notable professionals, retention and in some part, engagement is no. 1 KPI in free-to-play games since without, other KPIs of F2P game will decrease as well.

While "making a great game" is one of the main reasons for a good retention and engagement, I am not going to analyze the goodness of Modern War since it is largely in the eye of the beholder. What I will do, in the other hand, is to analyze the mechanics which affects the retention and engagement whether or not the game is good.

Core Loop

The most important aspect which affects to retention of freemium social game's is the core loop. In Clash of Clans for example, the core loop consists of three parts which is in itself complex enough but in addition, the outcome of the actions inside the core loop depends largely on the decisions made by the player, making it very compelling to master your skills in the game. In Modern War, the decisions made by the player for example in attacking other player's base, doesn't seem to largely affect the outcome of the action which makes it very hard for player to master the skills needed to make better decisions and thus, decreases the motivation to come back to game.

Feedback loop of PvP battles illustrated below.

PvP battle feedback loop, 1: select your opponent and decide whether to raid or attack

PvP battle feedback loop, 2: If decided to battle, this is the feedback you'll get during battle(!)

PvP battle feedback loop, 3: Outcome of the battle

Energy mechanics

In addition to core loop, in any free-to-play game where the progression speed of player in the game is reduced with energy restriction mechanic, primary engagement mechanic is the fill time of energy and the notification of the user when energy is filled. In Modern War, the energy fills up very quickly, in about 10 minutes (depending, of course, on the max cap of energy which the player has) and the stamina refills in about 5 minutes. Unfortunately, Modern War doesn't notify the user in any way that the energy has filled up making less easier for player to know that now is good time to come back to game.

Community and PvP

Despite the crappy feedback loop, the most effective aspect in Modern War which encourages players to come back to game is PvP battles and especially  the community around it and the time-limited live events with special prizes. 

Live events are most effective way to engage and retain users in Modern War.

Live events are the glue which ties PvP fights, rankings and factions together. Live events which start at certain time, last for certain time and rewards players with special in-game items which cannot be purchased from the shop. By creating short-timed live events, it increases the engagement as well as monetization because the true fans of the game will spend money to win those special prizes.

Monetization

Needless to say that when game remains in top ranks of grossing lists for so long, it is doing something right in terms of monetization. In order to fully understand how the money-making actually works, let's dive a little deeper.

In-Game Currencies

The game features soft (cash) and hard (gold) currencies, meaning that the player will earn soft money by doing missions = attacking enemy bases. Gold is earned very small amounts by leveling up, but that really means small amounts.

Player can spend cash to building and upgrading buildings and purchasing more - regular - units. Gold is used to purchase special units and building, fill up energy and stamina and also to speed up construction and upgrading of buildings. 

In my opinion, the game doesn't give the player enough hard currency so that he could get used to use it.

Different buildings cost different kinds of currency

Special items

In similar vein to live events, game features also limited-time campaigns which offer limited edition units to user to buy. These special units are typically very effective (either in attacking and/or defending) and as you might have guessed, these limited-time units cost hard currency, making it quite compelling for users to buy those.

Limiting the availability of units increases the motivation for users to buy them.

In-App Purchases

Users can buy both the hard and the soft currency pack as in-app purchases from in-game store. The minimum price for purchasing either currency pack is 4,49€/4,99$ which gives player 50 gold bars or 50 000 in cash. Prices starts to go higher quite quickly because the next price tier are 17,99€, 44,99€ and 89,99€.

According to App Annie, the most popular IAP is "Bagof Gold" for 4,99€ which, I think, is not a surprise to anyone because usually players tend to buy the most inexpensive option available.

Summary

To sum up the analysis, it is clear that the game is still making decent amount of money in App Store. Although the feedback loop especially in waging battles and defending home base could be a lot better, the game excels in creating a thriving community of players (as depicted in the game forums) who want to play the game, contribute to their faction and be in the top ranks of all players. I think the developers have been able to create a game where there is quite big tribe of true fans and the developer gets most amount of money from this thriving community.