Facebook
Estimated US People 91.2M
Estimated US People 91.2M
Youtube
Estimated US People 71.3M
Estimated US People 71.3M
Myspace
Estimated US People 63M
Estimated US People 63M
Estimated US People 21.9M
Flickr
Estimated US People 21.8M
Estimated US People 21.8M
Blogger
Estimated US People 16.6M
Estimated US People 16.6M
Digg
Estimated US People 12.4M
Estimated US People 12.4M
Reddit
Estimated US People 1.3M
Estimated US People 1.3M
Stumbleupon
Estimated US People 822K
Estimated US People 822K
Orkut
Estimated US People 445.3K
Estimated US People 445.3K