Facebook messaging

Alright guys so here's my question.
You see a babe on Facebook and you want her number. What works for you when you message a lady?

Just send a couple of good messages then get her number. Most of the time she will give her number to you.

I agree with that. I'm curious if anyone has just came out with it on the first message. "Hey I want your number" If you get it shows a lot already that she's interested.

Maybe I'm old-fashioned, but I didn't even add my last girlfriend on facebook till we were dating for 2 months.. she added me rather. Then again, I don't spend much time on facebook, refuse to communicate/meet women on the internet, and have had positive feedback from that stance thus far.