Coming from a service industry, I don't understand it.
Girls can go to a lot of expense and trouble to create and update a profile...then they get the biggest buying signal they can get when someone shows interest, and what do they do ?
Ignore it completely !
Unfortunately, the industry is dominated by girls that are low in the intelligence stakes, probably have never had a proper job and have no foresight regarding planning. Some may have professional looking websites but they are useless unless the girl matches up it. Yes, anyone that has had a proper job in a "customer facing" industry will pick up on the buying signals and react to it. A large majority of the girls can't even maintain credit on their phone let alone respond to mails correctly.
Some girls can't think more than a day ahead - they want a emails from guys that one to see them later today or tomorrow. A booking for 5 days away is beyond their capability to plan - they will get other emails for the day before a future potential and choose them instead. So maybe some girls will never reply - they read it in case it is an overnight booking or a big bucks meeting, perhaps?
I hasten to add that this is by no means all girls. Some are very logical, plan ahead etc., It would be nice if a girl would respond to at least say "thanks for email" I'll get back to you" but you will be lucky! Unless the the girl is interested in seeing you, she will not even acknowledge that you exist......
From the other side, one of my regs showed me that amount of emails she got in a day - and the stupidity of some of them - so I have a feeling that some just pick and choose the ones to respond to. Long emails are far too much for some to comprehend and they will just move on.
Makes me laugh when girls say that it is quiet out there when, with a little planning, they could have had a steady stream of business. They just want an easy life and some are just not prepared to put in any effort at all. No email back, to me, means their service may be equally as crap, so I just move one.