there are some people with very bizare sexual tastes out there. in some european cities you have red light districts with prostitutes who sit in very plain veiw, well lit up, for customers to take a good look at them. Often you will have an area where older women, often african, often obese, sit. they are no cheaper than the girls who are gorgeous thin blondes in their early twenties, but their is a market for them, go figure.
It makes life a lot easier probably to do it like that. I mean, you just select what you want to have, whether it is a tranny or a gorgeous blonde. This site has been in the news a lot the past year: http://www.hookers.nl/
. It basically is a site where people who visit these areas put reviews in of the hookers they have visited and give them ratings.