Here are the top 20 largest social bookmarking sites ranked by a combination of Compete and Quantcast data. For each site, we show unique U.S. monthly visitor data as well as respective rank.
The social bookmarking market is in a steady state with two dominant players - del.icio.us and StumbleUpon. The rest of the pack, including Yahoo MyWeb, appears to be substantially behind. Will they catch up? In this post we attempt to answer that questio