What are in-app purchases?

In-app purchases (IAP) occur when a user purchases an item in an app or game with real money. Some examples of what users purchase can be: an extra life, an upgrade to speed up a task, cosmetic items for a character, or hints for a puzzle. This is a way for publishers to generate revenue and can often be used in lieu of, or in addition to, in-app advertising. 

How do in-app purchases work?

In-app purchases can be offered to users at any time, and some games specifically wait for a turning point in a game when players are in need of assistance to move on to the next level. In-app purchases generate revenue for the publishers, and players get additional value from their app or game.