I'm trying to understand how free-to-play games like Candy Crush Saga use existing knowledge of the human brain to keep people engaged and how they convince players to pay money for in-game goods. Some of their game mechanics remind me of the Skinner box. Interestingly, some sources claim that a very small percentage of players contribute 50% of their revenue. I'm assuming this is because not everyone is as susceptible to their monetization tricks. Some addicted players dump all their money into the game, which puts pressure on game developers to protect vulnerable customers from themselves.
Research on big spenders in free-to-play games seems to be scarce, but are there any parallels with existing research (e.g. on gambling) that explain why many people will never spend a dime on these games while others are struggling not to spend their life savings on it? For example, is there a significant difference in how individuals respond to conditioning?