Well funny thing is, I think they think they're gathering demographic data.
Suffice it to say, when I register, its with a phoney email, and being a 14 year old girl from missoula would be more accurate than the rest of the info I give.
In fact, for the last two years I've been "Adrienne Beauregard" to so many web sites and junk mailers that I get almost as much mail (e- and real) for my female alter ego than I do for myself. I get magazine and newspaper subscription offers and have taken them when free. Send Adrienne all the bills you want! I could probably establish a false identity based on the volume of stuff with that name on it. Adrienne even had a brother Adrian for a while when someone misspelled the name and then spammed it to others.
So I hope nobody is making any decisions on this demographic data...