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.

Pocket Planes and F2P Design Rules

Although Pocket Planes hasn't been a huge commercial success, I think it is still such a good example of how to develop and publish a F2P game that I wanted to share some thoughts with you guys how the characteristics of the game transforms to the some F2P Design Rules set forth by Nicholas Lovell, and how that translates to money.

The Core Loop and the Complexity in Layers

The core loop of the game consists of operational level with completing the jobs and strategic level with expanding and building up player's own flight armada. The inner layer and the whole idea of the game is to get some people and cargo  in to the planes and move them to the location where the customers want them to go. This process is called as the jobs in the game.

The game features basic restriction mechanic which is quite low at the start, but increases quite heavily after a while. In the beginning of the game - and depending on the purchased cities (airports), accomplishing one round of core loop takes from 10 to 20 minutes. Usual reward of the flights is soft currency called bitcoins, but from time to time, there comes jobs with a reward of hard currency (Plane Bux). As the time goes by and player gains more experience, cities and planes, it might take several hours to complete one job increases the retention as well as the conversion of the players.

Player can access the boarding , airport upgrade and plane upgrare screens from the aiport screen.

Passenger and cargo have different kinds of destinations and  rewards

After choosing the jobs (passengers and cargo), it's time to decide the flight route for the plane.

Players can view tha plane and the passengers and cargo from the flight screen (and collect some in-game currency)

Does it sound too simple? It's not. Pocket Planes is a perfect example of baking complexity in layers. Every plane has it's own variables (level, capacity of passengers and cargo, speed, flight distance and weight) which translate to which airports it can use, how much cargo it can carry, how long it takes to complete the job, how far the plane is able to flight without stop-overs and how efficiently. Even without thinking the complexity of the outer layer of core loop, player can fine-tune the performance and reach of his flight armada based on at least six variables - enough complexity for most of us.

Outer layer of the core loop consists of buying and upgrading more and better planes, buying more cities and establishing different kinds of flight routes for player's armada. The decisions of course are based on the existing armada and the planned future plane purchases. Every plane and airport has level (1-3) which determines which aircrafts can  use which airports. Level one aircrafts can use all airports, but level two aircrafts can use only level two and three  airports and level three planes can use level three airports. The level system really deepens the gameplay, but at the same it isn't too complex to drive away more casually oriented players.

I must not fail

One great element of Pocket Planes is that the player cannot fail in the game; player can either earn more or little bit less, dictated by his decisions on the cargo, plane and the flight route. It's important to note that even if players cannot fail, it doesn't mean that they can't use and develop their skills. In Pocket planes. players get more rewards (cash and Bux) by tuning their plane armada's vatiables (planes, plane types, airports, flight routes) to optimize the cash flow.

The emotion of the player gets from the game is not that "I failed", it's more like "Wow, that's a great profit from the job" or "That wasn't perfect job, but I got profit. Next time, I will get more with less". Players always feels good after completing the job, but not completely satisfied which would kill the appeal and traction of  the game.

Evergreen story

It's important to note that in order to get the percentage of the player base converted and the retention, there's gotta be enough content in the game to get the players playing the game.

Pocket Planes has A LOT of playable content. There's 62 planes, over 250  cities and a lot of funny, special cargo and passenger for player to keep playing on and on and on...

Pizzazz and emotion

Another great element of Pocket Planes (element found in some other titles of Nimblebit; Tiny Tower and Nimble Quest) is that even though the graphic style is similar to 90's PC games, it's still creates very compelling and vivid world. This experience is achieved with several elements, such as actual names of the "bitizens" (passengers) in the airports, Facebook mock-up called Bitbook where players can see and share messages of bitizens which actually synced with the gameplay and progression of the player. 

Monetization and the no-brainer first time spend

As said above, there's soft and hard currency system in the game by which the developer can control that the player cannot get all the items in the game for free. 

Soft currency is mainly used to buying more airports, buying more plane slots for additional planes and to upgrading airports.

Hard currency is used to buying, building and upgrading planes and speed up the flights. Buying planes cost from five to 50 bucks, depending on the level and characteristics of the plane. 

Player is able to earn hard currency without spending a dime in the game. First of all, the player gains three complimentary Plane Bux every time he reaches a next level. Second, player can earn a lot of Plane Bux by completing jobs with hard currency rewards. Finally, few Bux can be earned by watching the plane during it's flight and tapping on the screen when hard currencies come by.

Hard currency can be bought with real money. The price points of the hard currency packs starts from 0,99USD (0,89EUR) which gives the player 20 Plane Bux, the prices of Plane Bux packs go on with 4,99USD (200 Plane Bux), 19,99USD (1000 Plane Bux) and 39,99USD (5000 Plane Bux).

My guess is that the main drivers for people buying hard / premium currency packs are the ability to buy better aircrafts and upgrade them. Second biggest driver of retention is the ability to build aircrafts from parts discovered from the newly bought airports.

In my opinion, the first price point is low enough (heck, it cannot get any lower)  to encourage players to take quite risk-free first step of spending some money to game. But honestly, I believe that Nimlebit should offer bigger and more expensive premium currency packs to enable players who have money and are willing to spend it to games, they can spend $100 with one purchase in the game.

Although I believe that game makers should be generous especially with F2P games, I think that Pocket Planes gives a little bit too much too often. With a bit of luck (in terms of being able to get a lot of premium currency jobs),  I could make up to 20 Bux in one game session. In average, the player can make 3-10 Bux with one session (in Level 13, one session takes about hour and half). I think that's little bit too much too often.

One great aspect of the monetization is that the player's can convert premium currency to soft currency in the game. With one Plane Bux, the player is able to get 500 coins. Because players are not able to buy soft currency with real money in the game, it's a nice way to enable players to spend more the hard  currency to speed up the progression (remember that players cannot buy Plane Slots or Airports with hard currency).

Conclusion

To sum up things, I think Pocket Planes is great example how to build F2P games consistently throughout the game. The fact that it's not in the top lists of grossing titles, might be due to little bit alternative graphical style which doesn't appeal to broad audience (as e.g. Hay Day appeals). Also, the genre of the simulation game (airline simulation) doesn't have the broadest appeal for the gamers.

Despite these facts, Pocket Planes is a great game, but not perfect example of implementaion of monetization  mechanics in the game.

Making money with arcade gem and diamond “match three” puzzlers

I must confess; I can’t stop playing kinds of games like Bejeweled Blitz, Candy Crush or Diamond Dash. I know that for some core gamers, those kinds of games represent almost everything which is wrong in current mobile / social games. They are very casual, playing the games doesn't require much time and focus only short bursts of time and you just can’t lose in those games. Also, what’s more important, they are almost always free-to-play. But I love the! I just love them for so many reasons, the first one being the gameplay experience. I really like that I don’t have to buy very expensive equipment (maybe except iPad) in order to play these games. Second, I love that I don’t have to sit many hours in front of the desk in order to play tem, but everything happens in short bursts. Third, I love how the developers have been able to do so different kinds of experiences with seemingly similar game play mechanics and core loop. And last, I love the amount of polish and perfection which some of these games posses.

In this article, I’m going to dive little bit deeper on how these games actually make money and how they are so good

Core Loop

The high-level core loop of these games is almost identical and extremely simple and quick. First, the player starts to solve puzzles which, in some games take the hard-coded one minute to solve as quickly as possible and in some the user has to reach the goal or be defeated. In most cases, solving puzzles costs specific amount of lives, usually one life for one try. Players can choose to wait that lives reload, ask friends to send lives or then pay real money for getting lives faster. After solving the puzzle, players earn XP, coins (soft currency) and variable amount of points.

When players has reached certain point or progression point, the player levels up which is showed to players’ friends in the social graph of the game. In some games, the game rewards players’ leveling up by visual representation of the progression,  in some game rewards player for extra content.

Key gameplay mechanics 

1. Simplicity

From the quick look, all of these games share same key gameplay mechanic: move items on the screen to match at least three same items next to each other in order to explode them and earn points. And this very simple mechanic is the heart and soul in every one of the game listed in this article. It is simple and quick enough so that the game is easy to open and play for short bursts in the go.

2. Depth (and diversity)

First impressions might be confusing, because in fact most of these games have little more depth than what eye sees from the first five minutes.

First and foremost, Diamond Dash and Bejeweled Blitz both feature one minute quick puzzle solving session which focuses the player to make quick decisions and try different combinations while on the other hand Candy Crush Saga doesn’t limit the time available but limits the amount of moves for session, and focuses the player to think and make smart moves in the session.

Let’s take a look for example to Candy Crush Saga and Bejeweled Blitz. The same core of match three mechanics is in both games, but in addition players are able to match more than three items next to each other, creating special items which have different features. One item might swipe whole vertical or horizontal line through when the player is able to match it with two similar items. In Candy Crush Saga, players are also able to mix different special items together creating super-special items which have very cool abilities. These special items add more tactical depth to very simple gameplay mechanic which compels to players who like to think and discover more special items.

Special and normal green candy item (Candy Crush Saga)

Jelly block and normal block (Candy Crush Saga)

In addition, Candy Crush Saga features different kinds of goals, restrictions and level elements in different levels which further add the depth of the gameplay. Typical restrictions of the game are number of moves which the player is able to make during one session. Goals of different levels can be tied to reaching certain amount of points, getting some number of special items all the way down and also, clearing jelly blocks from the level.

In Diamond Dash the depth comes from how the player is able destroy blocks of items from below so that he can create bigger chunks of similar items, resulting in getting higher amount of points as well as achieving special consumable items which he can use to further. Diamond Dash doesn't have as much depth as CCS, but it has some other specialties by which it is able to keep players engaged. More about that later in the article.

3. Level of polish (feedback on the player)

If Diamond Dash and Bejeweled Blitz are two oldest titles (released on Nov 7, 2011 and Dec 11, 2011 respectively) in App Store and Candy Crush Saga newer (released Oct 19, 2012) it also shows in the level of polish meaning in this case the amount and quality of visual and aural feedback which the player gets from the game.

When played on Retina powered iPads, Bejeweled Blitz has the lowest bar of quality of visual feedback of these games. But that’s not bad either. In Bejeweled Blitz the experience which the player gets from exploding items and using special items got from the four or more matches is great! In my opinions the visual FX and aural feedback which the player gets immediately after doing a successful move is one primary component of keeping players engaged in these games.

Visual feedback  from the use of special item in Bejeweled Blitz.

Diamond Dash is little bit better in the level of polish of visual and aural feedback. Especially immersive is the feedback from the “speed mode” which is achieved by getting certain amount of successful moves in a row within a short period of time (albeit the move is not correct word in this case). 

There is five or six moves which the player has to do successfully within the given time period in order to get to the “speed mode”. In this case, the aural feedback which the player gets from every step is brilliant! Aural feedback is presented by increasing the pitch of the sound FX of successful move, and so by increasing the pitch little higher from every move, causes the player to immediately recognize that now he is one step closer to the mode.

Great example how to send the feedback to the player about special mode in the game. Animated fire frames coupled with  great sound FX creates completely immersive experience for that brief moment of time.

Finally, Candy Crush is the ultimate example on what “polish” means. All the visual and aural feedback which the player gets from the game is tied into the overall experience of slow, relaxed and casual game-play where the focus is to think before act and make wise decisions during the core game-play.

There is no rush anywhere during the game-play and that is communicated to the player with relaxed, warm graphics and soothing – also meditation like music.

Albeit the theme of the game being a little bit naïve, the experience pleases the teenagers as well as little bit more matured audience of the west. 

Graphical quality is superb and the visual fx is super polished meaning that player gets from every successful move rich feedback whether the move cause three items to disappear (match three) or if the player is able to use some special items along the way.

Also, Candy Crush gives very direct and clear feedback of the progression (level) of your gameplay by showing the progression as a path of the young Princess (main character). The game also shows where does the player stand in relation to his friends (social graph) thus resulting in some cases of extra push for the more competitive players.

4. Lives (energy mechanics)

The first three mechanics described above describes how to keep players engaged and achieve better retention by focusing to things which matters most for players (in my opinion). This means that without superb core game experience, additional acquisition, retention or monetization mechanics doesn't bring the added value to the game.

But if these mechanics are integrated to core game experience in clever and unobtrusive way, they really add huge value for the developer (meaning that the mechanics doesn't break the core experience and doesn't scare away the players).

One mechanic which can increase the retention as well as monetization of free-to-play games is restriction mechanics. Restriction mechanics restricts the speed of progression for free-to-play gamers thus allows players to increase the progression either buying or asking it.

In Candy Crush Saga, player can have up to maximum five lives at his disposal. One session of puzzle solving costs one life. Lives regenerate at the speed of one life in a half an hour. If the players want to have lives quicker than by just waiting, they can ask them from a friend. Players can also increase the amount of maximum lives by buying three extra lives with real money.

In Diamond Dash, players have also up to five lives at their disposal and one puzzle solving sessions costs one life. Lives regenerate at the speed of one life in eight minutes meaning that lives are full in 40 minutes.  If player don’t want to wait that time, he can always ask from a friend or buy more lives with hard currency. In Diamond Dash, players can also buy more 15 seconds more time to one 1 minute game session with hard currency 

Bejeweled Blitz doesn't feature any restriction mechanics; it is completely free-to-play in apart from purchasable consumable power-ups.

5. Social elements

Social connectivity and viral invitation mechanics are crucial for any mobile F2P title currently due to rising user acquisition costs and discoverability challenges with App Store and the likes.

In Bejeweled Blitz, social elements are tied into competing against your friends through the top list which is connected to Facebook if the user wants that. In addition, players are able to show off their progression as Facebook status updates. Also, players able to give purchased power-ups as presents to their friends who are also playing the game.

As described above, in Diamond Dash, players are able to send free lives to friends or request those from them. The game also features weekly tournaments between friends (Facebook social graph) from which the winning player gets prizes. 

Candy Crush Saga is the best of the breed among these three games in terms of baking viral user acquisition mechanics in the game. Although not entirely innovative, Candy Crush uses extensively the Facebook social graph in it's core loop. First, there is the "give and ask life from a friend" mechanic which is quite popular in most of the Facebook games. Second, players are compelled to ask their friend's to unlock the next episode of  their Saga in order to proceed to next chapters. Third, the game uses social graph in two ways to increase the retention of the players by allowing them to see their performance against that of  their friends'. The first way is that the player sees his total progression in the game in relation to his friends' progression by seeing how far (in which level) he is from the start of the game. Also, after playing the level, players can see how they have performed in the level compared to their friends' performance - awesome technique to increase the retention for those who are more competitive than the normal joes.

Progression path coupled with Facebook social graph is clever way to use social elements in the game to increase user retention.

In my opinion, Facebook social graph social mechanics (send / receive lives, open quests etc.) are quite effective in engaging users to play more often and that way, increasing retention as well. This is because by default, Facebook automatically notifies when player has received a life from a friend. Also Candy Crush Saga has used ingeniously the social graph to increase user retention among the players who like to compete against 

6. Monetization

When numbers 1-3 concerns on what parts of "match three" types of games increases the player retention of these games, number four describes the free to play energy (restriction) mechanics which creates framework for utilizing the players who would like to advance faster and number five about how to implement viral user acquisition mechanics into the games, then the last element would cover how to make money with the game.

Bejeweled Blitz is perhaps the lightest game of the three in terms of monetization mechanics. The game features in-game currency (called "coins") which the players earn through playing 60 second rounds. The better the player performs, the more coins he gets. Players can also get coins from playing daily spins - lottery mini game. 

Players can use coins to buy normal and special consumable boosts in order to get better scores in the next rounds. Normal boosts costs from 3000 to 7500 and special boosts (called rare gems) which costs up to 75 000.  

If player wants to advance faster he can of course buy the coins with real money. There are several coin packs available, starting from 100k coins /1,79€ , and going up to over 9m coins with the cost of 89,99 euros.

In my opinion, the biggest amount of money comes from players who wants to use Rare Gems. First of all, they are so expensive that some players with deep pockets and short patience can buy those to advance more rapidly. Second , Rare Gems sound and look so stupid that they just have to be tried out. Finally, they are effective enough so that players want to try them again and again.

Cat's Eye -gem. Featuring crazy cat coming in the end of the round. Making crazy cat sounds and exploding stuff up. Not your typical power-up!

Diamond Dash features both soft and hard currency which are called coins and gold respectively. Player gets 10 - 100 coins from one 60 second round and one gold from leveling up.  Players spend coins to lesser one-time boosts before the next round. Gold can be used to buy more effective boosts,  to fill-up  lives (to advance faster) and to buy more time for the round at the end of the round..

Players can also buy in-game currency with real money. Both gold and coin  packs costs from 1,79€ to 89,99€.
My view is that that the biggest money for the developers comes from the players who would like to proceed faster and then buy gold with real money. 

In my opinion, Candy Crush Saga has implemented most effective system for monetizing players, even without using any type of in-game currency system. In Saga, there are several  layers where player can spend some dimes in order to progress faster, affect their result of the level or just add longer term effectiveness of the game.

At the highest level, players are able to buy Charms which are durable IAPs (cannot be worn out) and they  affect the long term variables such as maximum amount of lives. Charms costs from 14,99 euros to 21,99 euros.

View from the Yeti Shop

On the second level there are Boosters which can be bought from the level menu. They are consumable power-ups. Boosters are much cheaper than Charms, and they can be used in tricky situations when player is stuck into some particular level.

Finally there are Boosters which are offered to players on the occasion of failed level. At this point, players can buy five more moves if they got into the situation that they almost passed the level but not quite. Five more moves costs 8,99€.
In my experience, low-priced consumable boosters which are offered to players after the gaming session and which increase the chances of successful session, are most popular IAPs. In Candy Crush Saga, most popular IAPs  are Extra Moves and Extra Lives.

The games in rank

In terms of the six elements described above - the clear winner is Candy Crush Saga. The overall experience from the game is exactly what it should be; the core loop is simple enough so that even the most casual of casuals understands it, but complex enough so that it compels also the players who want to think.  The visuals are real eye candy  and the level of polish really awesome. Game is balanced enough so that the monetization mechanics doesn't break the overall experience but still gives great buck for the developers from the players who want to spend.

Second comes Wooga's Diamond Dash. Best part of the game is the visual and aural feedback which creates very engaging 60 second experience for the players. Core mechanics are very very simple, but still gives enough complexity to engage players for some time. Progression curve in the game is well balanced; players level up quickly during the first five - seven rounds, but then the progressions gets slower and slower. By the time player reaches level 20, it takes a lot of time to reach next level.
The game is clearly developed with casual players in mind, and thus lacks similar kind of depth than CCS.

The grand old Bejeweled Blitz comes third. Mainly for the lack of same kind of visuals and polishing than the Diamond Dash and Candy Crush Saga (at least in the free version), but also for the lack of not being able to get clearer feedback on the level which player has been able to reach. Now player has to tap his profile picture in the rank list in order to get any kind of information what is his level in the game. How awesome would the weekly rank list be when players could see their levels in addition to weekly points? This modification would allow player to  to compete in level-rank in addition to weekly points. 

Small games - big opportunities

In essence, "match three" types of game posses huge opportunities since the amount of work required for make them  is not tremendous (except, maybe, Candy Crush Saga) and the potential revenues are still huge (all of the three games are within top 100 grossing list overall, and Candy Crush in #1).

Before jumping onto the band wagon of match three games, one needs to remember that all of the games (and developers) above  have been very successful in Facebook and in dedicated online gaming sites. Transforming that success to mobile platforms is little bit easier to do than building gaming franchise from ground up.

In addition, the competition in the genre of these games is brutal. There are over 700 hundred games in App Store which have in their description "match three"; Jewel Mania, Jewel Masters, Jewel Stars, Jewel Fever, Cruel Jewels.. you name it.