You are forgetting a lot of stuff inbetween, not in the least the fact that even successful bands have a hard time making ends meet, major label or not.
Grizzly Bear, a very successful indie band recently had an interview where they spilled out everything. The band that opens for Radiohead and Paul Simon, is featured in ads for Volkswagen and Peugeot and sells out Radio City Music Hall.
They can't afford health insurance. After a tour they just about break even, and they make most of their sales from touring. Here are a couple of quotes from Twitter: "Mog and Spotify do not help bands or labels or indie stores. Not shaming you, just stating the facts since someone asked" and "Buying an album helps a band ten fold over buying a t-shirt, no matter what format. Again, answering questions".
The vocalist, Edward Droste, says that he doesn't even make a middle class living.
Here's the money quote from the interview: "“There’s a ceiling that independent artists hit,” he recently told NPR, “and the only way past it is radio.” And radio “still feels very much controlled by major labels’ ability to use leverage—you still have to have the muscle. Very few indie acts actually have breakthrough radio hits.”"
http://www.vulture.com/2012/09/grizzly-bear-shields.html