Thirteen percent of adult Internet users in the U.S. are using Twitter, up from 8 percent half a year ago, according to a a new report from the Pew Internet and American Life Project.
"Twitter is becoming less of a place to read what people eat for breakfast and more of a place where people can go for meaningful content," said Aaron Smith, a senior researcher at Pew.
Furthermore, over half (53 percent) are accessing Twitter on their cell phones.
Broken down, there are slightly more men than women on Twitter (13 percent vs. 11 percent), most have gone to college (16 percent), most live in an urban area (15 percent), and half earn more than $50,000 a year.
It's well-documented that most Twitter users are minorities, but Pew says the gap between African-Americans—the largest represented group—and white users is growing. In May 2011, there were 16 percentage points more African-Americans than whites on Twitter (25 percent African-American versus 9 percent white). Last November the racial divide was only 8 percent (13 percent African-American versus 5 percent white). One in 10 African-American Internet users visit Twitter every day, double the rate of Latinos and nearly four times the rate for whites, according to Pew.
There are also more older adults adopting Twitter than ever before: those in the 30-49 year old bracket doubled to 14 percent from 7 percent last November.
How is Twitter attracting an older, more educated, and African-American crowd? Smith said it's no coincidence that more than half of Twitter users access the microblogging service through their cell phones.
"The under-40 crowd and people of color are known for being active adopters of mobile technologies," he said, citing a recent report from Northwestern University. Furthermore the social network contains some active, influential minority users like Oprah Winfrey, Shaquille O'Neal, and Barack Obama, he pointed out.
"And obviously with the increase of smartphones, it becomes much easier to access Twitter no matter where you are, in a very seamless way. It works well for people who are always out and about."
The Pew study was based on phone surveys among 2,277 adults (aged 18 and up) between April and May this year.
Twitter's CEO, Dick Costolo, disputed the report, telling the AllThingsD audience on Wednesday, "There isn't a third party that correctly measures the Twitter audience."
That's true to some extent. Because Twitter has one of the lowest barriers to entry for a social network (you don't even need to sign up to access someone's Twitter page), it's more difficult to ascertain site demographics than it is for other social networks. Smith said that Pew opted to study usage rather than registered profiles.
Additional reporting by Lance Ulanoff.