Joining social networking and the popular game of chess is Chesspark, which runs the game in a flash interface, but also includes many social networking elements that no doubt encourage it’s visitors to keep coming back.
Perspective: Social niche networks like this will continue to grow, and Advertisers won’t be far behind. Determining which products to sell to these demographics is one challenge, but I believe specialised new product categories will emerge that directly target these niches such as customised chess boards.