Never buy a woman a drink in a club, unless you're on a date with her. I'm sure there's quite a few women reading this and rolling their eyes right now. Just hear me out.
In my single days, I took great pride in never buying drinks for women, because ultimately I knew it was just a waste of money. Why waste money on watered down, overpriced drinks just to get a woman's attention? You buying a drink has absolutely nothing to do with whether or not that woman thinks you're attractive.
As a matter of fact, there are plenty of women who specifically go out at night with the goal of getting a guy to buy them drinks. These women have no intention of giving out their phone number or going home with someone.
The absolute worst offenders are the females who have the nerve to ASK you to buy them a drink. A female who does this is NOT interested in you at all. She's only asking because she's done it before, and some guy is always dumb enough to buy her one. If a woman is truly interested in you, she would be too afraid of asking you something like that because she'd be too worried about offending you. If a woman ever asks you to buy her a drink, there are two correct responses. The first response is "No." The second correct response is "I'll buy you a drink on our first date."
I broke my rule about buying drinks ONE time. This was about 15 years ago, and the friend I was with asked these 2 women to sit down at our table. He was interested in one of the females, and proceeded to buy her a drink. I just shook my head, but I didn't want to look like a cheap ass so I bought the other woman a drink as well.
We were all talking for about 10 minutes, and the two women said they had to go to the restroom and would be right back. Well, I knew what was happening but I decided to let it play out. Sure enough, five minutes later those same women were out on the floor dancing with two other guys, drinks in hand. I pointed this out to my friend and stated "THAT is why you don't buy females drinks."
Stop wasting your money on women that aren't really interested in you. If you really want to spend your money that badly, just give it to charity. At least you'll feel better about yourself afterwards.