Who's on Twitter?

18-to-34-year-olds. This group is 41% more likely than the average internet user to visit Twitter.com, followed by 35-to-49-year-olds, who are 11% more likely. It also skews female, with women being 4% more likely to visit the social site.

Who's on Tumblr?

New Englanders are 41% more likely than the average internet user to visit the social-media platform, followed by West Coast folks (24% more likely) and Mid-Atlantic residents (11%) more likely.

Myspace

Who's most likely to be on the site? Southerners. People on the West Coast are 26% more likely to visit the site; in the Southeast part of the U.S. are 15%; people in the southwest are 6% more likely. Who's least likely? Upper Midwesterners, by 25%.

Who's most likely to use Facebook?

In a word, women. They're 5% more likely than the average internet user to visit the site; men are 5% less likely. From a geographic standpoint, likelihood to visit Facebook.com is pretty even throughout the country, but it definitely skews to 18-to-34-year-olds, who are 11% more likely than average to hit up Facebook.com.

Who's hot on LinkedIn?

Men. Males are 5% more likely to visit the site than the average internet user, while women are 5% less likely. It also skews particularly high among folks ages 35-49, who are 33% more likely to log on to LinkedIn.com.