Buying women drinks only work if you want to get her drunk!
This may also work on Gold Diggers. If not, you will end up falling in the category of supplicating and you will be de-valued.
The objective of a seduction is to be able to pickup without giving away any form of material wealth. Buying women stuff to make her happy is no different than paying for sex.
General rule:
Don't be extra nice to her unless if she earned it.
Otherwise, she knows what you want.
Only when she has earned or proved she has done something special for you, should you consider buying her a drink. If you do it for no reason at all, then you have revealed your interest in her and she takes charge.