You'll need a little more than just free games to play to attract surfers. You've got a whole bunch of sites out there with prizes being offered to their free players to compete with. Most of the people end up on sites like Pogo and Yahoo Games.
One thing you might want to look at is
www.gamehouse.com. They give you the games to imbed in to your pages and the opportunity to resell the pay versions of the games. They were bought out by RealArcade, so the affiliate program is here -
http://www.realarcade.com/gmhsprg