Think Twitter’s just for kids? Think again. According to a recent report by comScore Media Metrix, the leading age group in terms of “most likely” to use Twitter is the 45-54 group (36% more likely than average to be a Twitter user). The second highest-ranked group is the 25-34 (30% more likely than average).

Twitter demographics

Other social media sites like Facebook have recently seen a surge of older users, but like MySpace, most social media services were initially adopted by the younger crowd, and their elders followed along later.  Twitter is a rare example of older people embracing a new Web 2.0 technology early on, according to Andrew Lipsman, director of industry analysis at comScore.

Why?  Twitter is for business — and business owners are quickly catching on to the fact that Twitter is the ultimate tool for relationship marketing and for building your business network.  And as more people come aboard, the more valuable Twitter becomes, which in turn entices more people to come aboard, and so forth — sort of the eBay phenomemon.

One more interesting note: 5% of Twitter users are 65 and older.