Twitter has seen enormous growth in the past few months, having gone over the 30 million users mark recently. With a lot of media coverage and high-profile celebrities using it, Twitter has gone mainstream but according to a new study by the Participatory Media Network and Pace University it may not be such a hit among the younger generations. The study showed that only 22 percent of 18- to 24-year-olds used Twitter.

While almost all of them – 99 percent – have profiles on a social network like Facebook or MySpace, only one fifth have a Twitter account. This would seem to indicate that website's rise in popularity has been mostly in the older demographics and less so among college students and teenagers. The survey also showed what the young people that were using Twitter were doing it for. Of them, 85 percent used it to follow friends, 54 percent to follow celebrities, 29 percent for family members and also only 29 percent for companies.

"Twitter dominates the news, but clearly we're only touching the surface of its potential as a marketing vehicle," Participatory Media Network Co-founder and Chairman Michael Della Penna said in a press release. "This is a classic 'glass half full' scenario for Twitter because it's clear that Gen Y has an appetite for social networking, but still hasn't fully embraced micro-blogging. There is a tremendous opportunity now for marketers to develop strategies to get this important group active on Twitter too."

This may not be such a bad thing for Twitter as this would mean that there is still a lot of growth potential for the micro-blogging service. But it is somewhat discouraging for companies using Twitter as a marketing tool because the study suggests that it may be reaching only a small percentage of the younger generations.