Too Long; Didn't Read
When developers work on a game, they need to test the validity of their ideas. Usually, hyper-casual game publishers test product metrics even before developers start making the actual game. The most important thing is to find out if users will install the game and to do so almost for free. In order to evaluate the demand, publishers use a variety of metrics, such as CTR, CPM, CPC, and the main one known as CPI. These terms might look confusing at the first glance, but all of them are quite simple to understand.