Lady Gaga has established herself as the unchallenged queen of Twitter, becoming the first to have 20 million followers – two million more than any other user on the site.

A relatively early adopter, @ladygaga joined the site on 26 March 2008. Unlike other stars she runs her own account, using Twitter to chat directly to her "little monsters" as she calls fans, post pictures and share information about tours and releases. She took over as the most popular person on Twitter from Britney Spears in August 2010.

Like any Twitter user, a smattering of recent tweets reveal Lady Gaga's key obsessions. "Told you MINT would be big in fashion this spring. Naturally, I will continue to wear black. (perpetual mourner)," she informed her Coke-can headdress wearing fans. A recent tweet about a cookie – "The chef at hotel made me a surprise. So awesome to see the message spreading already. One cookie at a time." – inspired 179 comments.

A tweet on Valentine's Day gave fans some sage advice: "Happy Valentine's Day everyone. If you have someone special, give them a kiss. If you don't, make a voodoo doll of your ex and cast spells."

Despite an ever-morphing number of experts, commentators and political leaders on Twitter, the five most followed people all come from the world of pop. Lady Gaga leads the pack, with teen star Justin Bieber following close behind with 18 million followers. Statistics from twittercounter.com suggest Gaga's daily Twitter growth rate is consistently higher than Bieber's, meaning her supremacy looks unlikely to be challenged in the near future. Katy Perry is in third place with 15.7 million followers, with Shakira fourth with 14.5 milllion and Rihanna fifth with 14.4 million.

Barack Obama can only manage eighth place with 12.84 million followers of his @barackobama account.

Lady Gaga's online presence is key to her success, which saw her sell 8m copies of her latest album, Born This Way. As well as 20 million Twitter followers she has 48.8 million fans on Facebook and is in approximately 830,000 circles on Google+. She recently launched her own social network, Little Monsters, which gives her fans an outlet to create or share Lady Gaga-related content, and communicate with other fans to show whether they like what other users post.