Pet friendly seems to be a big draw for us. We travel with our dogs and know just how difficult it is to find places to stay that are truly pet friendly.
Only rarely have we had to do any real extra cleaning (muddy weather) due to pets (we do not charge extra cleaning fee for pets), and one time had damage caused by a dog being left unattended (against house rules, fortunately they paid, with no argument). We have never had complaints about dog hair, odors, or allergies.
The only real added expense is that of the good sturdy fencing for the yard, and we wanted that for our own purposes anyway.
Vacuuming and mopping is going to happen regardless. We ask guests to be with their pets at all times, inside and out, keep pets off the furniture, including the beds, and of course to clean up after and dispose of waste properly.
It seems to us that people who travel with pets understand how hard it is to find pet friendly accommodations and are willing to do what it takes to keep them pet friendly.