I have used Crowdspring for a product naming. We got a few hundred names.
Most were junk. Many users didn't seem to read the instructions. But we did
get 10-15 good names. In the end, we didn't end up using one of the names
(though you still have reward a winner to your favorite). I consider it a
brainstorming exercise more than anything. $400 or so, so pretty low risk.