I tried it couple times. I didn't do it ever again because I felt that the people I met when I was pretending to be someone else were either not worth my time or someone that I'd want to get to know and I didn't want to mislead.
I pretended to be a male business exec, a male construction worker, or a single female college student studying psychology. I chose things that I knew at least a little something about - business exec: I run my own business and I helped Dad run his for years - construction: I worked construction all the while I was growing up and now and then now even - College: I went, took several general psychology and several child psychology courses.
I created a different profile than the one I normally used in order to 'be' that person without repercussions. It was a useless endeavour and a waste of my time really. I'd rather role play in the bedroom.

__________________
"Always learn the rules so that you can break them properly." Dalai Lama
My Karma just ran over your Dogma.