It's been talked about over and over again on the forums and the general consensus amongst the providers is that they are here for YOU. Many can and will orgasm but it's a good idea if that isn't what the session is focused on. Some have basically stated to not even bother. Just be clean & courteous, get yours and be happy.
For the majority of women an orgasm is just as much a mental as a physical thing. Guys too but the mental bit tends to be on a much lower scale.
I do my best at trying to put my date at ease with me by being myself (i suck at putting on a second face which would likely lead to apprehensiveness). If you can get a lady to relax and feel comfortable around you then chances of her achieving orgasm are going to at least be within the realm of possibility. Sometimes that might mean a couple of visits like T1 mentioned. When I have a session it involves some catering to her because it's part of what I enjoy. So technically it is still all about me