I think the answer to your question is two fold. People have a certain "value" about them which I believe is determined by your personality, earning power, looks, etc.
If a person is inherently lower value than you, they'll be attracted to you simply just for your value. Again, it's all subjective, but I think there are some fair lines to draw. (I.E Brad Pitt is of higher value than me).
So, being uninterested is just a by product of your assessment towards her, you recognize she's lower value and you act accordingly.
Not to mention too, attraction is all relative. If you started banging a bunch of 10's all the time, it wouldn't be as cool as the first time obviously, and it would just become your new standard.