[mpk]

I wouldn't attribute that to race but rather to it working well for the needs of a small subset of a demographic (trend setters) and as they use it more, others join in.

It would be interesting to see twitter networks broken down by demographic and an analysis of what each group uses it for. Some people use it to convey social information ("I'm in the checkout line at Walmart"), others as a stunted form of IRC ("Oh no, you did not just say that!") and most of the people I follow use it as a substitute for email where the primary purpose is to send links around.

If anyone feels compelled to do the research, I'd love to read your findings.