I think that's different. In arcade's example, the only reason you needed a coin is when you have used all your lives. Now, if you had better skills, you could

I think that's different. In arcade's example, the only reason you needed a coin is when you have used all your lives. Now, if you had better skills, you could get through the entire game without a single additional coin. In IAP module, the game is designed so there is no chance (at least for 99% players) to go through the game without purchasing the stuff on the go. Take "where is my water" for example. You can continue game as long as you keep scoring all 3 coins on each level. If you miss even one coin, after many levels you will be missing that coin to open another level. There you have an option to open the level for $$$ Now, some of those coins, in my gaming experience, were impossible to score, but that's a different story...