More often than not, the picker and the pickee are equally aware of what's happening. It's an elaborate mating dance more than anything else - one that happens to end up in the sack. What, did you think women preen themselves for a night on the town out of some virginal and innocent hope for True Love(tm)? Men and women in clubs/bars are there for similar reasons.
Personally, that's not what I'm looking for, but I constantly wonder what of the PUA community I can pilfer for my own ends - certainly, their methods for generating initial interest should be of interest to anyone, even people like me who are looking for relationships more than sex.