about 2 years ago - Ahskance - Direct link

Twitch engagement is a form of advertising because top-watched games are recommended more easily to new viewers.

Yes, the idea of watching instead of playing to receive rewards can be odd if taken on its face, but having an extra 10, 100, or 1,000 viewers hanging out in your game's category still helps draw others to check it out. People go where the action is, so viewer count is very important in that sense. "If others are watching it, maybe I will too."