If they are touring, or using a hotel, advance bookings are beneficial as they know the money from the punter will cover the room and travel costs.
Last week I emailed an escort called Chloe Willow asking for a meet in Manchester, at a hotel I was in, and after a delay of several days loggin in, she logged in twice in 2 days, didnt read my email. So I deleted it. Her fecking loss, as it was for 1.5-2 hours. Another I emailed was good enough to say she was moving to London, so would not be there, fair enough.
In a way, I dont give a toss they get 70+ emails, it's their business, they chose it and they need to manage it better.