Seems reasonable to me; see the full post and related story for more details
There are many reasons that teenagers use Twitter less than adults do, including fundamental differences between what teenagers and adults want online and between Twitter and other sites like Facebook. (I take a deeper look at these reasons in a story in Wednesday’s paper).
But one big reason for the disparity is simple: When Twitter became popular, teenagers already had their favorite Web sites for communicating, so they were not interested in a new one. The people who discovered Twitter were adults who were new to social networking.