My maximum booking time is 1.5hr, I couldn't stand anymore than that. Unless someone is really really hot, interesting and funny, I can't do the long, boring, exhausting bookings. And because maybe 1% of all the clients are really really hot, interesting, funny and in my preferred age group, I only do 1,5hr max.
I don't advertise half an hour, as I am outcall only. I have a couple of half an hour regulars though, and they are actucally the easiest money ever, so I might consider advertising this... But I'm worried that I will start enjoying half hours too much and then won't be happy with my longer bookings, so might keep it as it is.
I used to do all the horrible overnights and several hour forever-dragging-ever so-draining meets, but not anymore and I am 1000% happier.