I shall explain this a briefly, though this is an excellent write up about the epitome of ladies night.
Every bar's business model is based on getting women into their establishment. The reason is simple - men will buy drinks for both men and women. Women won't even buy drinks for themselves. In other words women themselves aren't really ever viewed as customers as much as they are in fact marketing.
Sadly this means most night clubs are really nothing more than "more polite" strip clubs designed to extract money from men.
YOu guys really do have a choice. You can just refuse to go to night clubs. Not saying you won't hook up. Not saying you won't get a phone number. But for the time, effort and money you have to expend to do well at a night club, there are plenty of places where you'd do much better.