SomaSim does their revenue sharing a little differently. They treat everyone's hour equally - an hour of coding or design is the same as an hour of art or an hour of QA. That means if art hours are 35% of the game's total development, then artists get 35% of the revenue. Matthew talks about the awesome parts of this model.
For the video version, please visit https://www.youtube.com/watch?v=ihN0RF52MZE
https://twitter.com/MatthewViglione
http://www.somasim.com/blog/
Game Dev Unchained