It is a studied fact that both myspace and twitter have been more adopted by the popular music scene (hip hop, pop, rock) than other technologies, and that both have much higher percentages of black users than other similar sites on the Internet (and in the military, it was mainly enlisted using myspace, and officers using facebook; guess which one they blocked after 3 months?) This article, for example: http://www.slate.com/articles/technology/technology/2010/08/...
"Urban" seems like a pretty fair term for teenaged/young adult hip-hop and related culture people, which does include more black people than the general population. However, a black 40 year old college cs professor or engineering professional is more likely to be on facebook (or linkedin, or researchgate, or hn) than twitter, so it's not really a racial thing, it's cultural, which is probably more tied to age and interests than anything else.
"Urban" seems like a pretty fair term for teenaged/young adult hip-hop and related culture people, which does include more black people than the general population. However, a black 40 year old college cs professor or engineering professional is more likely to be on facebook (or linkedin, or researchgate, or hn) than twitter, so it's not really a racial thing, it's cultural, which is probably more tied to age and interests than anything else.