Agree with Dr... A lot of what you do to pick up women also applies to keeping them. Most folks lose their women because they go against what attracted them in the first place. The only difference is, you have to maintain what you were doing in the beginning - while also giving more as time goes on. People like a challenge, and the feeling that they've earned someone, but there has to be a prize to get. You can't have them chasing you forever - while acting like a selfish prick. They'll get tired of it eventually, and probably hate you for it. This is why a lot of jerks get women, but can't keep them.
I heard someone once use the volume bar as an analogy. You can't raise the volume up all at once (giving too much) - because everyone will get scared away. But you can't keep it on mute (not giving at all), either. Gradually, you raise the volume up, so that no one is overwhelmed or caught off guard... Until you find that right balance. I think this is a perfect summarization of relationships. Little by little...