App users and casual gamers like those who play Candy Crush or Sudoku have come to tolerate the interruption because either the app is free to use or they earn a reward for watching it. Advertisers like these ads because they drive actions. Typically, the ads include a call to action (CTA), usually asking the user to download a new app or take some other action. This type of ad, even though it appears within a game, is still considered an in-app advertisement.