When I wrote last week's column comparing the social-networking sites MySpace and Facebook, I included a line after my signature stating that I had only 124 friends on Facebook, and urged readers to add me as their friends. As of today I have 261 new Facebook friends, the majority of which are Generation Y college students.

I turned to Hitwise data to find out more about them. By examining which websites social-network users visit after logging into their profiles, we can gain a bit of insight into how sites like Facebook fit into their members' daily online lives. The data showed that after other social networks, the most clicked-on category of sites was search engines, with 11.6% of all downstream visits. Web-based e-mail services were next with 8.5%. Blogs came in third in popularity at 6.1%, claiming more than four times the number of visits to traditional news sites, which logged 1.5% of downstream visits.

Perhaps a more interesting — and more accurate — way to figure out where college students are going online is to assess which of the 172 web categories tracked by Hitwise get the most hits from 18- to 24-year-olds. Here's a shocker: Porn is not No. 1. I've actually been puzzled by the decrease in visits to the Adult Entertainment category over the last two years. Visits to porn sites have dropped from 16.9% of all site visits in the U.S. in October 2005 to 11.9% as of last week, a 33% decline. Currently, for web users over the age of 25, Adult Entertainment still ranks high in popularity, coming in second, after search engines. Not so for 18- to 24-year-olds, for whom social networks rank first, followed by search engines, then web-based e-mail — with porn sites lagging behind in fourth. If you chart the rate of visits to social-networking sites against those to adult sites over the last two years, there appears to be a strong negative correlation (i.e., visits to social networks go up as visits to adult sites go down). It's a leap to say there's a real correlation there, but if there is one, then I'd bet it has everything to do with Gen Y's changing habits: they're too busy chatting with friends to look at online skin. Imagine.

This reshaped online landscape leaves me feeling old and out of the loop. It seems that social-networking sites have not only usurped porn in popularity, but they've also gobbled up time Gen Y-ers used to spend on traditional e-mail and IM. When you can reach all of your friends through Facebook or MySpace, there's little reason to spend time in your old-school inbox. So, if social networking is becoming e-mail 2.0, then perhaps Microsoft's recent $240 million dollar payout for such a small stake in Facebook isn't that ridiculous.

The reality is that Facebook isn't just for kids. Last week — and this was a highlight — my dad, who just turned 75, added me as a friend on Facebook. I considered sending him a virtual beer to celebrate the occasion, but I didn't think either of us would see the point. Back in my day, we drank beers out of bottles and cans — we didn't have these new-fangled virtual beers. But, then again, I think that's something I probably still have in common with the younger generation, something I don't need Hitwise data to back up: the love of a good old-fashioned beer.

Let the messages roll in.

Bill Tancer is general manger of global research at Hitwise

and i actually like the fact that you can't design your facebook layout. i like the organization and uniformity as opposed to all the bullshit on myspace and (some) xanga.

and i actually like the fact that you can't design your facebook layout. i like the organization and uniformity as opposed to all the bullshit on myspace and (some) xanga.

and i actually like the fact that you can't design your facebook layout. i like the organization and uniformity as opposed to all the bullshit on myspace and (some) xanga.

Currently, for web users over the age of 25, Adult Entertainment still ranks high in popularity, coming in second, after search engines. Not so for 18- to 24-year-olds, for whom social networks rank first, followed by search engines, then web-based e-mail — with porn sites lagging behind in fourth