It's one of the reasons agencies can keep costs down to £100 as they often cram in bookings 15 minutes apart - which for the really popular girls can be stressful as it allows no time to be flexible even if people are only five minutes early or late or over run slightly.
Can also lead to bad practices like clock watch, running out of clean towels and condoms, or checking texts or missed calls in your time as the next punter is stacked up like planes over Heathrow. Combine that with shared flats and the risk of punters clashing and it creates some of the problems people complain about on here.
Indies can leave 20 minutes and many leave at least half an hour as it makes their job less stressful so they can clean up, change bedding or towels and means they are more likely to be able to offer extras like uniforms or outfit requests.
Of course they can't fit in as many punters in an eight hour shift - and some on here then twist their nose up if they charge £110-£130 an hour to cover that. But the choice is yours.