By Kim Walker / Silver Group - As of January, more than 50% of Facebook users and 44% of MySpace users in the U.S. were over 35 years old, based on ComScore estimates. The single biggest age demographic in the U.S. on both Facebook and MySpace is now between 35 and 44 according to a Feb 25 report in Advertising Age.

This is consistent with the UK where 49% of social networking users are over 35 and where 55+ users jumped over 6% between 2006 & 07 while at the same time users 18 - 24 fell by -3.5%!

According to research from Hitwise, Facebook has more users with incomes above $60,000 than MySpace, indicating an older, wealthier audience. Right on!

But will the presence of older users turn away the young set? not according to eMarketer analyst Debra Aho Williamson who said "Social networking is so engrained into the lifestyle of college students that it wouldn't be any less cool because their parents and grandparents are there."

So what does it mean for marketers that social networking is getting older? For Facebook, the upside is they're now being considered for a wider array of marketing budgets. "A year ago, they thought about it as a place to reach people in college or high school; now we're talking about moms, or reaching families looking to go on vacation," said Kevin Barenblat, CEO of ContextOptional, which has implemented Facebook campaigns for Guinness, Microsoft and the Los Angeles Times.

Another remarkable stat comes from Second Life reporting that the 45 and older are their heaviest users, spending on average 70.17 hrs per month pretending to be somebody else!