I would say in Adelitas the girls don't really care if you buy them a drink or not, and in fact many of the hot ones think it's a waste of time. Now I understand the chicas have a drink quota to make, so they don't mind the drink.But the first thing they ask you if you want to go upstairs with them, fuck the drink! If you don't say yes, then they say, ok how about a drink.
This is one of the reasons why I recommend this bar to all first timers as all the girls go upstairs here, no bullshit like they are on their period, and it doesn't make a difference if you buy them a drink or not......your getting the same service..hopefully it won't be bad?
The other bars yes, it's customary to buy the chica a beer before going upstairs, but not mandatory, but sometimes if you don't buy them a drink, they will tell you no they don't go upstairs.