I know it's generally not a good idea to get cd-keys from eBay (and other sites), but I started wondering how this works. Today I saw 2 auctions offering Left 4 Dead keys, for less than 1/3 of the normal price. One had a 100 keys, the other 80. Both claim that the keys are new and unused. Judging by the comments to their profile, people are mostly satisfied, so everything is working. How the hell does someone get a hold of so many keys and sell it so cheap? Are there some Steam Key generators out there or something (obviously don't post links)?