I don't agree with a number of people above, even Star to a point. I think it depends on the club and the individual dancers.
My g/f enjoys the clubs as much as I do, so we're usually together when we go, sometimes a few of my buddies are with us, other times some of her friends have been with us. At least 75% of the time no dancer will stop by our table unless my g/f is gone to the bathroom. EVERY time she's gotten up to head to the bathroom, then a girl will come ask if I want a dance.
9 out of 10 times my girl has to either stop a dancer walking by, or go up to one of the stages with some singles. Personally, I think dancers are LESS likely to approach if you have a girl with you unless you and/or her are well known in the club. They're intimidated or something if you have a girl with you, I suppose because they assume you forced her to come with you or some shit.
And mind you, neither my g/f or I are bad looking people. 8 out of 10 times my g/f gets asked by the dancers if she is (or would like to be) a dancer...that's after she's approached them.
Just my .02 from personal observation/experience.
Oh yeah, and one correct statement above: the majority of dancers are bi, not lesbian. How could they be around hot naked chicks all day and NOT be bi?!