I'm not suggesting that all "Thanked" posts are frivolous, far from it, but would it be fair (for example) for someone who posts a "Joke of the Day" thread and who receives a ton of "Thanks" for making people laugh to then be considered for a discounted developer device? Yes, they probably deserve something for helping to brighten up the place (a T-shirt perhaps?) but maybe not a device that could go to someone more focused on code or fixing problems...

Having a system that differentiates between simple "Thanks" and a "Reputation"/"Useful" score might prove more beneficial in the longer term - comparing the two scores may also elicit useful information regarding the nature of the members involvement within the community/forum.