I do petsitting myself but do it for free for friends. I don't know about businesses but I make two visits per day and stay for at least an hour each visit and get some play time in. Fortunately my job allows me to set my own hours (within reason) to accommodate this. If the kitties are outdoor kitties I make sure the floor is clean before the owners come back. If they are gone for a longer period, I'll also vacuum. I like the owners to come back to a clean house. Sometimes I will even stay overnight to give them extra loving....