Americans still dominate the upper reaches of the Twittersphere, but techies and bloggers now represent only a small proportion of the user base, according to stats published by Netherlands-based Peer Reach. Pop stars such as Lady Gaga and Justin Bieber now have the most followers, but they are not far ahead of Chinese stars on Sina Weibo.
American actor Ashton Kutcher (@aplusk) won the race to become the first user with more than a million followers, but this is no longer enough to get noticed. According to the Twitter Counter website, at least 760 Twitter users have now joined the millionaire club, though Peer Reach puts the number at "over 1,300".
Peer Reach's pie chart shows that most millionaires are from the US, followed by the UK, Brazil, Indonesia and Spain.
In Twitter's early days, most users worked in technology in some way. Many were involved in social networking, blogging, web development, tech journalism and marketing. They were the sort of people who went to the SXSW conference, where Twitter made its initial impact, as Peer Reach's graph shows.
Today's Twitter is more evenly spread following the influx of users from the media industries -- music, television, film etc -- and sport. Most early technology-based users are now bit part players, and Microsoft's Bill Gates has become the "top techie" with 9,279,696 followers.
Twitter now has about 650 million users, with Lady Gaga being the most popular (32,835,572 followers). However, she will soon be overtaken by Canadian pop star Justin Bieber (32,577,149 followers), who has been closing the gap for some time.
The top of the Twitter chart is dominated by pop stars, with a few notable exceptions. These include US president Barack Obama in fifth place (27,706,815 followers), footballer Christiano Ronaldo in 16th (15,241,231), and his Real Madrid team-mate Kaka (19th; 13,937,959). Twitter users now need more than 10 million followers to make the top 30.
It's not a foregone conclusion that either Lady Gaga or Justin Bieber will retain the honour of being the world's most popular social network user. Chinese actress Yao Chen now has 31,759,700 followers on Sina Weibo, which is the Chinese social network most like Twitter. However, Yao Chen's long reign as "queen of Weibo" is being challenged by the Chinese American pop star Wang Leehom (right), who currently has 28,581,296 followers.
Weibo has about 400 million users, but given the size of the world's Chinese-speaking population, it could overtake Twitter one day.