is the rover fee taken from owners and sitters?

I think that you need to look at the larger picture here and how much really goes into having the benefit of having a site like Rover. There are a lot of expenses involved with the website. If you ever noticed how many different dog words you google and Rover is one of the top sites that appear. (In other words Rover is paying a lot of money to keep their listing high on the search engine so it draws more clients to the site) The more clients to the site the more business in turn for us. Also don't forget the support that Rover gives us. It may have not happened yet ( and we all keep our fingers crossed that it never does) but when an accident happens beyond our control, Rover does support us with not only there staff to help defuse the situation with an angry client but they also keep us covered with an insurance plan. Imagine that something happened to a dog in your care and ended up in the emergency room for thousands of dollars. (and before anyone thinks I am exaggerating when I say thousands of dollars, think of the cases where a dog has to be hospitalized for: hit by a car, ate a sock or foreign object and needs exploratory surgery, got bit by a rattle snake during a morning walk, ect. (The list can go on and on for how many accidents can happen beyond your control.) I guarantee you at that point the 15% will not seem like very much. Had it not been for Rover you would not have ever even had the chance to meet some of your clients. And yes I hear about the dedicated sitters that keep their clients going through rover -They do get rewarded by having their posts higher on the list of sitters. (Repeat clients is one of the ways they rate us in determining our placement on Rover. So incense they do reward us.)
As far as clients, I do agree with you. The clients need to feel appreciated. Having a customer loyalty program would be nice. After so many bookings with the same sitter you get 1 free night. Even with the $20 off.Rather than refer a friend and the new clients gets $20 off while the person who referred them get nothing. I think that the offer should be refer a friend and they both get $20 off their next stay. It encourages the client to refer more friends and family seen that this is a way for them to earn discounts towards their next stay.

The over all picture is that there is always an over head cost to keep any business up and running. Between the advertisement, the licences fees, the insurance, and the support staff- the 15% sitter fee and '% they take form the client is all worth it to me in the end.

Best of Luck and hope this help ease your mind, Take Care!