Oh Yeah and always start off the 1st message with the intention to book.
Imagine the tons of messages they get a day, they won't have time to respond to your queries such as "do you provide xxx service", "do you xxxx this" .. all their services are clearly listed on their ad..
Put yourselves in their shoes, would you rather respond to a customer who says:
"Hi I want to book your time at 8pm" (guaranteed business)
or a customer who says:
"Hi Can I check if you provide full nude massage?"