I also am not a fan of the “Send us a ton of traffic/players” contests because for one, I just don’t trust the results when there is no supporting information other than a first name and last initial.
I think the gift card is perfect as well as the surprize gift that arrive with no strings attached. 
Income Access and Referback are two that have sent me gifts out of the blue, one of which was a wedding gift which was very thoughtful.