Here is an article on how the internet affects "the hobby," complete with puns like "more bang for your buck" and "going down."  It includes rates taken from "an international review site."  Gee I wonder what site that could be?

Some tidbits;

-Boston is the most expensive city, Montreal the least expensive (in North America) of those surveyed.
-The average rate declined steadily from 2006-2013 and rebounded slightly into August.
-The average rate increases for each increase in hair length from chin, shoulder, below shoulders to very long.
-Same for bust size going from flat to A, B, C to "D and above," the article concluding "breast implants may make economic sense."
-It's still more important to be "athletic" or "thin" rather than have "baby fat" or be overweight.
-Kissing and spanking apparently have a higher mark-up than anal sex.  I question their methodology on this one.
-A degree increases earnings by 31% but "more lucrative working patterns rather than higher hourly rates explained the difference."

see this thread from a couple of months ago:

https://www.theeroticreview.com/discussion_boards/viewmsg.asp?MessageID=201237&boardID=21&page=12#201237