The most popular accounts on Twitter have millions of followers, but what are their demographics like? Twitter doesn't release this data, and even things like name and location are only voluntarily added to people's profiles. Unlike Google+ and Facebook, Twitter has no real-name policy, they don't care what you call yourself because they can still divine out useful information from your account activity.
I've looked at one small aspect of demographics: gender, and used the first names of people following 99 of the most popular Twitter accounts to estimate the male/female split of their followers. In brief, the method made use of Social Security data to link first names with genders probabilistically, and ignored those accounts with obscure or fake names that couldn't be matched.
Here are the results:
Turns out One Direction have a lot of female fans while boys are more into sports, who knew!
There are a few more interesting results in the chart, however. Who'd have predicted that Lil Wayne (@LilTunechi) is the account with 50:50 split of male and female followers? While Justin Bieber, who you might think would be at the top of the table, actually has a much more diverse following with around 41% male subscribers -- equalling Lady Gaga.
Those more popular with male Twitter users include President Obama, with a 59% majority male fans, and Bill Gates (67%). The most skewed accounts of all were those of ESPN and Wayne Rooney, with 82% male followers each.
If you have a Twitter account, their analytics service will make an estimate of how many of your followers are male or female -- where would you be on this chart?