It is an advertising cost for the whore. She knows if she allows some diddling at the bar, then she is more likely to get take out and the trick knows she is liberal with the goods.

Like if I'm at the strip club and the ho asks for one for the kitty, after I put a dollar in her tits, If she pulls the panties way out, so I can see vag and she lets me run a finger over it, I'm more likely to get a couch dance than if she holds a hand over the cooch and pulls out the string on the side.

Generally if they do the string pull, I'll ask them to trun around, so I can tip the ass.