TechCrunch has techcrunched some good data on social sites for October 2007 compared with October 2006. The biggest news? At its current rate of growth, Facebook would surpass MySpace in total unique visitors a month within 2 years. Now it’s probably unlikely that Facebook will keep growing at 118% a year, but its growth still destroys MySpace’s at only 28%.

LinkedIn’s growth is even better (though the site is much smaller) at 257%. This is surpassed only by Digg (280%), AIM Pages (320%), and IMEEM (720%). While Windows Live Spaces looks pretty sad at only 4% growth for the year, it’s much better than Yahoo’s Geocities which went down 11% and Classmates which lost 1% (which is likely why they’re rushing forward with that IPO).

You may notice that AOL and Yahoo! dominate the social sites losing viewers, yet the two also have two of the best performing properties in Flickr for Yahoo and AIM Pages for AOL. This brings me back to the reminder I like to give Yahoo! at least once a month now: you own Flickr.

Yahoo! has been pumping out new social site after new social site trying to catch the wave after their failed attempt to buy Facebook last year. Yahoo! 360 folded, I haven’t seen any activity on my Mash profile in weeks, and I don’t even remember the names of some of their other efforts.

According to this data Flickr – which Yahoo owns – is a solid #3 on this list behind only MySpace and Facebook in terms of unique visitors a month. In the past year they’ve shot past Windows Live Spaces, Anglefire, 3 AOL groups including Hometown, Classmates, their own Yahoo! Groups, and they’re getting close to their own Geocities. Yahoo appears to have a very robust social network, they just don’t realize it.