How much do game creators get paid?

Can you elaborate on the payment structure for game creators in the industry? Are there any standard rates or does it vary based on factors like the popularity of the game, the size of the development team, and the platform it's being released on? Also, are there any additional sources of income that game creators can tap into, such as in-game purchases or advertising revenue? I'm curious to know more about the financial side of game creation and how it can impact the creative process.