Yes. Ninja loses 15,000 subs every day he doesn't stream [0] (The linked article is a super interesting profile -- definitely recommend it).
[0] http://www.espn.com/espn/feature/story/_/id/24710688/fortnit...
[0] http://www.espn.com/espn/feature/story/_/id/24710688/fortnit...
Amazon Prime subscribers are '5 seconds of fame' subscribers. His core audience has stabilized to pre-Drake numbers as of December, around 5-6k tier 1 subscribers. Note, subscriptions on Twitch are different from 'follows.' Subscriptions have direct monetary value and follows are indirectly valuable metrics (analogous to subscriptions on YouTube).