I'd lean towards the "carrots" myself, and there are lots of potential ones (user customizable profiles, more simultaneous games, "pro" games, etc). Look at wh

I'd lean towards the "carrots" myself, and there are lots of potential ones (user customizable profiles, more simultaneous games, "pro" games, etc). Look at what other successful startup multiplayer game sites are doing and try some out. With carrots, you can still offer a compelling free service but there are lots of appealing things that dedicated users will pay for. weewar.com seems to have succeeded in this, for example (I've taken my wallet out for them in the past, just don't have time for games these days otherwise I'd still be on there). I would think the key to retaining free players is the quality of the game(s) themselves, and the network effect of having enough players to play against. Checkers probably wouldn't retain me for more than a game, but some of the others on your site seem like they might. Scrabulous seems to be exploding on Facebook for example, while only one or two people I know play Chess... (unfortunately ;) Maybe a unique game like Lost Cities from flexgames.com -- that was a neat game for a while that you can't find anywhere else...