Is the fact that subscriptions are recurring accounted for? If you get 1k subscriptions a month at 2.50 each, on month 2 you make 5k, no 2500 (assuming no drop off)

Also, I would say that the vast amount of streamers revenue comes from donations- Its trivial to see this is the case, just watch a large stream in action like sodapopping or the like, and you will see "blah has just donated x$" show up on their stream every 30 seconds or so.

FWIW, I am fairly certain the top streamers make over 50k a month very easily. However, those numbers drop very rapidly. The top 20 streamers most likely make as much as the next 5000 combined. And those 5000 make more than the next 10,000.