I agree with everything everyone is saying in this thread. Respond to request asap, that will bump up your ratings in your zip code search! When I first started I looked at the top sitter's profiles to see what they had posted in the about me section as well as what type of photos/services they offered. How can you stand out!?
But I do want to mention that for Rover sitters such as myself, I am booked months ahead with repeat clients, so my availability is very limited, even then I would take a repeat client over a new one. That is what helps you build your business because they look to sitters such as yourself that have the open availability hence it will help grow your business!
One last tip, make sure you have a great write-up in your profile, I have a very long detailed one. I described who I am, hobbies I have, also why I got in the dog sitting business & if they booked with me what the communication would be like (my standard rule are updates 2x day with photos/description). Really make them feel like they are getting to know you before you even meet in person, that will make your meet/greet very easy as well. Treat it a bit like a dating website, get my drift?!
Good luck!