So, who among you has had this situation confront you: your parents send you a Friend request on Facebook. I have to admit that when my 73 year old parents told me they had a Facebook profile several months ago, I couldn’t believe it – since they are not really computer savvy and I never thought they would actually be able to figure out how to complete a profile. But sure enough… there they were. I thought that was pretty harmless in my wildest dreams I never thought they would figure out how to actually “friend” me. A few weeks later imagine my surprise when a friend request from both of my parents wound up in my inbox.

Well, if this article can be believed, a lot of you have been faced with a similar dilemma. According to Inside Facebook, the number of US women over age 55 using Facebook grew by 175.3% since September 2008, making mature females among the fastest growing demographic groups on the social network. The blog also goes on to report that membership by people 45+ has grown by more than 165% among both men and women in the last four months.

Some say that this means that the young-uns will soon find a new place to hang out as friend requests from parents become more prevalent. I say just the opposite. Porting a network of hundreds of friends to a new site is just not likely, especially when privacy settings on Facebook allow you to essentially protect the stuff that you would not want your parents to see.

I think, if anything, this is just more evidence of the staying power of these networks. The challenge now for marketers is to figure out how to add value to the experience that people have while on those sites keeping up with the friends. Facebook Connect is one clever way to allow users to travel the net with their friends and things like MySpace Music adds value to the user experience on the site by allowing users to buy the music they are listening to. As we have been telling brands for a while now, social networks aren’t just for kids anymore. And figuring out how to motivate and monetize those interactions isn’t child’s play either.