Not really a shooter specific question but...
I have recently purchased a used copy of COD Black Ops and it could not be installed because the key had already been used. STEAM does not release keys for used games. Fortunately the ebay seller was honorable and immediately refunded me. There is nothing on the box to indicate it is a STEAM game but in the root director of the CD there is a file called "SteamServices.exe". I found on amazon a few seller listing used copies of Black Ops (PC). Does anyone know if STEAM has exclusive retail rights to this title and I should give up finding this on the cheap?
Happy New Year!
Robert

Thanks Kramer, When I use Stream, I like it. But they kill PC used games and even now that its been superseded, they still want $45 for it.

I noticed quite a few used games that require Steam on e-bay that are up for sale.
One stated 'serial number included' and 'a Steam account is required'.Yes,theirs.
I wonder how many buy them and don't get their money back?

yeah, I got lucky. Even on Amazon there are allot of used "unknown" Steam games.