We don't necessarily need it, but it does tell us when your birthday is.

It also tells your age – thus experience. (yes, we know, age can be a BIG issue among gays, but please be professional about it)

If, for whatever reason, you feel uncomfortable using your real date of birth on your profile, please use a "fake" DOB. But again, be professional, this is NOT a dating site and age is something to be proud of!