The hugely popular micro-blogging service Twitter has come from a standing start in 2006 to become as well known as Facebook in the US, with African Americans proving particularly keen on “tweeting”. Some 87 percent of Americans know what Twitter is, compared with just 5 percent two years ago, giving it almost the same visibility as Facebook, which wins 88 percent awareness. But according to a study by the polling firm Edison Research, actual usage still lags far behind. Just 7 percent of Americans are on Twitter, while 41 percent are on Facebook. Twitter users tend to be disproportionately young, affluent and technology-savvy. And, in a curious finding, Twitter is particularly popular in the black community – 25 percent of US users are African American, roughly double their representation in the overall population. A report last year by the Pew Internet & American Life Project found 26 percent of African American internet users tweeted, compared with 19 percent of white users. In encouraging findings for advertisers, 44 percent of Americans on Twitter are aged 18 to 34, while 24 percent live in homes with annual income above USD 75,000 compared with a national average of 18 percent. Twitter, founded in Silicon Valley four years ago, dipped its toes into the commercial sphere last month by introducing “promoted tweets” that integrate ads.