Have you ever wondered why women bleach their hair, whiten their skin, enlarge their breasts, and invest so much into shampoo and conditioners to wash their long hair?
Leaving aside the cynical common-sense answer, here is an economic rationale:
because such investment pays many times over in money and services that the males offer in return, stupid!
In fact, it can be measured.
See this brutally frank The Economist's analysis of the earnings of female prostitutes: