I know it makes me a bit more likely to buy games, knowing that I can give them back if I don't like them. Before when you bought a game, you were commited. I got starforge and legends of dawn and have been stuck with them ever since. starforge is an unfinished rush job and legends of dawn is an almost criminal mess. Havn't really been able to convince myself to buy anything since legends of dawn burned me so badly.
Don't buy legends of dawn, even if it were free, it would still cost too much.