I sit in an airport playing candy crush. These people are geniouses in the most horrific way. Like a sparkling jem that absorbs your soul. Or a toad that if you turn up the heat slow enough. It won't jump. It'll sit there happily and die in a boiling pan.
From my time playing candy crush. I can tell you that the way they weave IAP is all about addiction. How it works is something i'm not sure if i single dev can pull off.
When you start the game. They don't really give you a whole lot. But the levels are crazy easy and crazy colourful and the sound that goes with it is similar to gambling slots where they splat tons of color and throw fireworks everywhere. It's building the player up that they are winners. That's just one facet on they beauty these guys put together.
Another is story. A story in these games do not need to be complex but they need to be cute.. That you're going down a trail helping random happy-go-lucky creatures out of their troubles. Peggle uses this as well as Candy Crush. Peggle goes a step further and has a Unicorn help you through the starting maps like a tutor.. If you play Peggle, Why is an anthropomorphic unicorn with questionable sexuality important? pandering to the younger audience is the answer.
You make the gamer feel accomplished that they are particilating in the story. that they are helping.
Another one of the really big facets in Candy Crush is duration.. This is the part that a small developer may have problems with. You see, these guys know how a cel-phone gamer works.. If you hit them with IAP's they'll uninstall your app with the quickness.. BUT! if you say nothing for hours.. let 30-40 and in candy crushes case almost 80 levels go by without a single IAP peep. The player is going to feel invincible. That they can do anything. They feel this way from all of the free power ups you give them at the end of each level.
At first you flood them with powerups! You point it out to them over and over again that if they are having a difficult time on a map they can use one of those 'free' powersups to get through it! You get them used to using them with the knowledge that if they beat a level another chance to spin a wheel and get a power up is around the corner. Oh! and you can also present the player with watching an 'ad' to get a power up.. see, your not even asking the player for money! just 30 seconds of their time.
You attack the player from different angles this way. They get a lolli-pop bomb thingy.. then a few levels later.. Oh look.. your collecting gold bars! Now you're introducing virtual currency into the game.. But you still have not asked for their wallet yet! these gold bars can be used to buy extra lives.. or power ups.. or a chance to come back from the dead giving you 5 more turns for a (possibility) of finishing a level. Oh yeah, this is the point where you can mention that you can only hold so many gold bars and if they pay you just 3 bucks you get a piggy bank that not only allows you to store more bars.. but be rewarded with extra bars everyday! But you don't have to get it! BUUUUT it makes playing the game nicer right?!?!?
Another major ingredient candy crush masters is chaotic level difficulty.. you'll be cruising really fast through the game and suddenly you hit this level that is a fucker to pass.. Now if your hyper conservative that would be the time to use those power ups the game keeps handing you and power for it.. After you pass that level.. the 5 levels after are remarkably easy.. the 5 after that are hard.. but passable.. the 5 after that are super-easy.. and BAM.. another fuck you level.. Developers have this beleive that level difficult is an upward hill that you must climb and the higher you climb the better skilled player you are.. Players think the same thing!! But what if the hill never goes up? What if it's just a sloping bike trail with the occasional barded wire fence every 4 miles?
That barbed wire level is what they are betting on. That you'll get used to using power ups.. that if you just use them a few times. You'll start using them on levels that aren't bad but instead you want to power through the game.. Why? you want progression in your story! You want to rank higher then your friends.. you want to level up in something where level is meaningless!! And you always jingle the IAP out there as a reminder that things can go super-easy if they just dropped 10 bucks on power ups! they might even fly right past 25 levels in under 10 minutes.
The developer adds more obsticles and monsters that could potentially crush your player. but they're always in the background! Because some of your players are playing just to get the poor ginger girl unstuck from the caramel mountain.. and they can't wait to get on that plane at the end of the sets of level to see whats next..
The developer does not challange the player as much as your pandering TO the player.. The developer wants them to feel good. that the player is winning.. that they've come so far in the game. look at you Player 1! you're on level 96! that's almost 4 pages of scrolling through levels.. not realizing that as a company you're adding 30-50 levels per month to your game. totalling almost 1000 levels. There's some that are in the 300's. but by then. how much did they spend?
One of the biggest things i've seen developers do for games like this and fail. Is there is no such thing as the word 'no'. There is no 'game over'. Instead, there is choices. When a player has failed at doing something too many times. the game will say "whoah! your out of re-tries for today. come back in 15 minutes for a free re-try... OR!! you could post something that your playing this game on facebook to replenish your re-tries.. (promotion botting people) OR!!! for only $1.. you'll get all of your re-tries back! See now you're not even selling powerups.. you're selling a means for the player to play the game harder instead of smarter.
While all of this happens the developer decides to smash that emotion button. You could show the main character sad. Or the little girl still trapped in caramel moutain.. throw in that jab of guilt.. What? Don't you want to save her? She can't wait for tommorow.. If you pay something right now.. we'll get you right up to the last level where you can free her and watch her say thank you.. only to go to the next level where jimmy ate too much chocolate and can't fit through the door.
Finally, the developer plays the mantle of responsibility onto the player. As a company and developer. You don't want the girl stuck in the mountain (even though you placed her there) that it's all up to the player And you're on their side! and you want to help make that happy ending come true! even if it's short lived and fleeting.
Daily currency boosts to retain player base.. e-mails. SMS Pushing. Nothing is off the table to remind people to come back and play more.. Ultimatly spend more. This is probably why Candy Crush outperformed Fortnite three fold in terms of revenue stream. They are machines and they are monsters.