Roughly two months ago Spymaster, one of the first Twitter-based RPGs, launched and spread like a viral wildfire through the tweets of thousands of users. The game grew quickly by making direct use of the Twitter graph as key events were automatically tweeted to all affected parties as well as all followers of that player.
Unfortunately, this element of the game did cause a tremendous amount of seemingly uncontrollable spam (which iList has since done its best to mitigate). However, it was never really their fault, as most of the blame rests on Twitter themselves and their general lack of more robust filtering systems. Nevertheless, the game pushed forward, and now Spymaster has released support for a much larger social network: Facebook.
Users who play Spymaster through Facebook Connect will not actually be able to play the game inside Facebook. Working in the same fashion as the Twitter updates, the game will utilize Facebook Connect to let users share updates and invite friends. Best of all, players will be able to compete with each other regardless of which network they are using.
Spymaster is in an interesting class of social games that run on their own website, yet rely on third party social graphs for identity and distribution. Whether or not this approach will catch on as broadly as games inside Facebook and MySpace is still to be determined, but the game is growing quickly so far.