Significant age differences exist within the user bases of different social networks a new study finds, noting more than half of users are 35 or older.

Myspace attracted heavy growth in the last month, according to analysis released on Thursday by research firm, comScore Networks. Teens aged 12-17 accounted for nearly a quarter of Myspace traffic in August of last year, however this year they represent slightly over 10 percent, the firm finds.

Conversely, Internet users between the ages of 35-54 now account for 40.6 percent of the MySpace visitor base, an 8.2 percentage point increase during the past year.

As social networking sites have become mainstream, the demographic composition of has changed considerably. Last year half of the site's visitors were at least 25 years old, while today more than two-thirds of MySpace visitors are age 25 or older, continued Mr. Flanagan.

It will be interesting to monitor the shifts in Facebook's demographic composition, he noted, referring the company's recent decision to open its doors to users of all ages.