It isn't an exactly what you're asking but in terms of giving away software and still making money on it with games - there are some people making money with free flash games. If I remember right the desktop tower defense guys made a little under 100k in a year and I read an article not long ago which suggested the ninja kiwi games website was making something near $30k/mo.<p>Or how about the farmville / zinga games offers where people do certain trial offers to get points in the game?<p>These seem like reasonable answers to your question (though these aren't open source they are still free to play).