In my fantasy world of the demimonde, gentlemen trade the handsomely printed calling cards of their favorite courtesans with the reverence of Victorian gentry. In the actual Valley version, it's done with databases.
At The Erotic Review and My Red Book, clients post Yelp-y reviews of their experiences. You can search by name, phone number, or URL of the woman you're looking to hire. Is her "kitty" trimmed? Does she smoke? Will she bring another girl? Does she go for rimming — and do you mean her or you?
Consumer Reports, it is not. Like Yelp, too many reviewers flaunt how impossible they are to please. And on most sites, you can get free access to reviews if you contribute one yourself, so writeups veer into bad "Penthouse Letters" territory.
That said, throwing keywords into a template-driven, searchable index of potential dates is fast and effective, more so than visiting the individual websites of the ladies in the listings. Compare the cock-stirring photos and easily-parsed text entry for NicoleCMT (pictured at top, massage only, guys) on My Red Book with her oh-so-generic personal site. We need a W3C standard for arousal.