First, here's the article: The Power of Reciprocity (crossposted from r/socialengineering).

Now, as we all know, buying girls a drink is a bad idea. But don't let this discount the idea of reciprocity. Let's break down why buying a girl a drink is a bad idea:

  1. It's too common. A hot girl can almost always get drunk for free because guys are always buying her drinks.
  2. It's too transparent. Buying a girl drinks is a traditional part of the mating ritual. If you buy a girl a drink, she knows without a doubt that you like her, so she doesn't have to work for your approval.
  3. It costs money. I have enough expenses without spending money on women that I may never get back.
  4. It puts you in the position of asking her what she wants to drink, which is you following her lead, not her following yours. You could just order her something, but that puts you in asshole range. There's no socially calibrated way for her to receive a drink she'll like and for you to maintain frame.

So, if I'm saying all this, I have a solution, right? Here's my trick:

This works best if you're not sitting directly at the bar. Get up and get a glass of water from the bar for yourself and the girl. If it's not just the two of you, get a glass for everyone there (assuming you can balance them; I worked in food service for a while so this isn't usually an issue). If there are too many people in the group, just get four or five glasses, keep one for yourself, and put the rest in the center of the table (for whoever wants them). A pitcher is also often an option.

Why does this work?

  1. It's not common.
  2. It's not transparent.
  3. It costs nothing.
  4. You're not asking; just do it and you'll maintain frame. In fact, by removing your presence temporarily you can actually improve your frame. Leave with the one-finger raised, "Wait one second" for extra points.