ok, sometimes B&W works for the best, and most of the time its a total disaster. Most of the times, in my experiences, it has been a disaster. So, I will only comment on my experiences. Okay, we as hobbyist search for providers we see, and that is who we are expecting to see. Our minds are stimulated and we are mentally prepared for our encounter with that specific provider.
Now, I haven't done this in the past, but now I have to because I found it necessary to do so. If a provider does not have a review, if she is not working for an agency, and if she post on BP or something of that nature, I always ask if the pic is real, and specifically tell them to be upfront or I will leave when I show up. If its not them, they will be honest with you if you ask them, they are not offended (some girls want to keep their identity a secret). Some girls will hang up, don't be disappointed, that saves you time b/c they are fakes. Sometimes, they will describe what they look like to you on the phone if its not their pics.
Ok, now suppose they have blatantly lied to you, even when you mentioned that you will leave when you show up. Okay, so you arrive. In my experiences, if I find that I am not attracted to them, I simply tell them that they look nothing like the pic & lied about it, and simply say, "sorry, this is not gonna work out" & leave. They can't do anything about that. They can't force you to do anything you don't want to do. In some small instances, if the provider wants to give you a hard time & ask for a cancellation fee. Simply tell them, "you need to reimburse me for my gas and time", and get the hell out of there. Its usually nothing more than that, ain't no body gonna stop you from walking out, & its nothing new. If however, you find that you are somewhat attracted to the person & have even told them they lied about the pics, sometimes its a bonus. B/C, once I tell them that, and I find myself somewhat attracted and need a release, ask them for a discount or you will leave. From my experience, it usually works out & they will give you a discount, and they always seem to perform a bit better too 
I found out that it only benefit the provider if you take these measures, b/c it will ensure their honesty in this hobby. Don't be afraid to ask them under those three conditions (more if need be), and don't be afraid to tell them in person either. They ain't doing you a favor, your the one doing them a favor by them luring you into their spider web of deception. Anyways, its not rude.