The Twitteration gap

Is it my imagination, or has Twitter become the Facebook-for-fogeys?

This very issue came up in my undergrad startup class last week, when we talked about Facebook & Twitter business models. Most of the students used Facebook, none used Twitter. Sometimes I wonder if the reason Twitter has taken off in certain circles has less to do with the tool itself than the sense that it's finally something on the internet older folks glommed onto first.