On OP's topic, another trick, used very effectively in League of Legends, is to mismatch the cost of store items and the premium currency (in-game cash equivale

On OP's topic, another trick, used very effectively in League of Legends, is to mismatch the cost of store items and the premium currency (in-game cash equivalent). $15 buys 1500 credits, the intended purchase costs maybe 800 - people are more likely to repeat purchase, exploiting the sunk cost fallacy. Intermittent reinforcement is commonly exploited in the form of thinly disguised gambling in games, it's a huge part of Valve's sales (crates) in Dota 2 and Team Fortress 2. A few common monetization strategies for skill games: - Selling shortcuts. Players don't really mind being given the options of spending money or additional time in game, barring extremes. Indeed, if not made available by the game vendor, this is often handled by 3rd parties - the market for in game currencies is measured in billions of dollars per year. These shortcuts to a goal can be seen in many games that merely sell additional options which have minimal effect on gameplay. - Cosmetics and other status items. Team Fortress 2 is a good example - people will buy anything that makes them look different from everyone else in multiplayer games. - Limited time products. Lots of games have started selling bundles (in denominations like $50 and $200) to early adopters that let them distinguish themselves from those who started playing later on or did not pay up. Path of Exile and anything by Perfect World are examples. Games without any multiplayer elements would likely find it hard to use these.