The Mariekko chart below shows how many sites social US news users get news from. Each column represents a social site and the rows indicate the percentage for their US users that get news from just that site, 2 sites (that plus another), or 3 or more sites. The width of each column represents the percentage of social news users that use that site.
Facebook has the largest number of social news users and 50% of them only rely on Facebook for news.
This chart was built with the Aploris chart creator add-in on PowerPoint for Mac.