President Obama’s following on Twitter topped 10 million people for the first time this week, capping months of steady gains on the social network despite sagging approval ratings in the polls.

@BarackObama is now the third-most-followed Twitter user in the world, according to  Twitter Counter, which tracks the social network’s 14 million users.

Only celebrity pop artists Lady Gaga and Justin Bieber eclipse the president, with 13.5 million followers and 12.6 million followers, respectively. Obama is immediately trailed in the standings by Katy Perry, Kim Kardashian and Britney Spears.

The closest politician to Obama in the rankings is former California Gov. Arnold Schwarzenegger who ranks 149 th with 2.1 million followers.

Former House Speaker Newt Gingrich has the most Twitter followers of any of Obama’s potential 2012 Republican challengers, with 1.3 million.

An Obama campaign aide said the 10-million follower milestone, while “not earth shattering,” is a “new and exciting” development for supporters who have been hungry for some good news.

To mark the occasion, the campaign website is hawking a “limited edition” T-shirt for Twitter followers that lists the president’s first-term accomplishments with hashtags.

Here’s what they include:  #DADT, #AffordableCareAct, #EqualPay, #CreditCardReform, #WallStreetReform, #IraqDrawdown, #MiddleClassTaxCut, #CleanEnergy, #AutoRecovery, #HateCrimesBill, #StudentLoanReform.