The listing, Invite to FREE steam keys site has ended.
Invitation to gameminer.net (gameminer.ru) - the web site where you can win lots of steam keys and gifts absolutely for FREE (i.e. no money needed)!
But unlike other giveaway sites, this one will not let you sign up with the steam account you have unless you also have an invitation code.
I won six games there, which include such titles as Mafia 2,Crysis 2, and other (totaling up to $700) - all for FREE.
Please note that you need to have Steam account to be able to access the site! (otherwise, why would you need free steam keys for?)
The winner will be given the invitation code with the instructions on how to access the site.