Two Social Media Sites Close !

    Two social media sites have closed.  The social news-ranking site Thoof and social music site Social.fm (formerly Mercora) have shut their doors, TechCrunch and GigaOM reported.  Thoof was launched in July 2007 by Freenet and Revver and based in Austin, TX.  Thoof is now redirecting to news ranking site Reddit. 

The other closure, Social.fm started operation in 2005 and was originally named Mercora.  The service initially focused on letting users create their own streaming radio stations, and later launched more social music discovery features, but struggled to gain a following against much larger rivals like Pandora, Last.fm and iLike.

Social media sites can be a boom to bloggers and help you find readers, but it's important to be on the sites most appropriate to your blog and the ones with the best potential for you. 

What social media sites are you on?  Which ones have given your blog the best results???