A little of both, depending on the "class" involved, and the location.

You might be surprised to learn that a lot of prostitution happens during the day-time. In largish-hotels a bloke going up to a room, spending 30-60 minutes there, and coming down wouldn't stand out. Even if the same host entertained 5+ people in her day.

(Unless you get involved in high-end work you'll virtually never have an overnight booking. Average duration amongst the people I knew was 60-90 minutes.)

I was not under the impression it was common for several clients to be booked during the one night.

I believe the girls would either use the hotel room for:

a) A place of work for regular specific bookings: it has the benefit of not being at a brothel/not at their home if they aren't comfortable with that, and it can become a familiar place and you'll be "reasonably" safer than going out to a clients house.

b) A way to work if you're in a different city/having another girl coming from another city.

Obviously, if you remember your freakonomics, there are levels to the prostitutions market. So there is the possibility of:

c) Its a place to drum up new business. I imagine places like hotels in Washington/Canberra where people are there on business, have money, and are away from their families, is, in the prostitution business, a place of relatively high demand. So the clients might have a room there that they're already paying for...

Now to be fair, this is at the relatively upper-end of the prostitution market.

Ironically, in the context of my other discussions in this thread, in this country at least, if there's a super low-end part of the prostitution market, i'd expect it to be operating out of illegal brothels...and probably out of unmarked houses out in the burbs...

The state of the flat is unfortunate but goes with the territory for AirBnB / hotels etc.