http://www.gamasutra.com/salarysurvey2014.pdf?_mc=AD_HS_LE_G14MRKEE04
Pages 1-5 talk primarily about the larger developers, and have some interesting data in them, but I'd like to concentrate on the indie stuff here (page 6). This includes all categories of indie devs, from solos to small teams.
- The average indie salary for 2013 was $11,812, down 49% from the year prior. On the one hand, it was a bit more respectable last year, which implies it won't always be this bad. On the flip side, such a large change in just one year indicates a ridiculous amount of volatility. Also worth noting: the survey only included developers who made over $10,000 in 2013, and were capped at $200,000, AND were limited to GDC attendees. So the cheap clone makers and the Notches of the world were excluded.
-The average indie salary for a member of a team (two or more developers) earned $50,833.
-Just over a quarter of indies got income via contract work instead of just their own game(s)
-Most attention-grabbing, fifty-seven percent of indie games (solo or team-developed) made under $500 in sales. Two percent made over $200,000.