"...knows what she's getting into."

I ask that all please offer a very detailed explanation of what this "what" is exactly that all these shes are getting into. Because it seems to me that the implication is that these shes should know better and that this business transaction is not a goid one at all on the shes end. That implication seems clear. Set me straight if I'm wrong. But if it is (which it is) why do you take such conscienceless joy and delight from a product based in such an inequity?