If I give a woman gold jewelry in appreciation of her love or her beauty or her kindness to me, her acceptance of it is its own reward. If I gave her jewelry with the expectation that I could then have sex with her, that is manipulation (unless it had been previously agreed upon that the jewelry was a de facto fee for sex).
I once had a female co-worker do a small, kind thing for me at the office. Next, she wanted me to spend my lunch hour running her errands for her. That is manipulation. The kind thing was not requested and there was no agreement on my part that I would do anything in return for this kindness. She just assumed that if she did something nice for me, I'd be willing to run her errands. She guessed wrong.
"Manipulation", like "discrimination", are words that have become emotionally-staked to mean worse than what they really mean. In my mind, manipulation is when you do something for someone with the expectation that they will be coerced to do something you want them to. It's the second half of the equation that makes it manipulation, not the first.
If I buy a woman a dinner, or a drink or a car, I'm not expecting anything in return unless I announce it before she accepts it. If she wants to respond in kind, that's great. If she doesn't, that's life (at least my life).
But then again, women are always telling me I'm "too nice", "too kind". etc.