Hi Shelby:
I'm also a travel sitter that offers the same services as you do.
Have you gotten business cards from the Rover store? If so, you can drop them off at local businesses in your service area. (Pet supply stores, groomers, etc). Also, you can share the link to your profile on your local Buy/Sell/Trade sites on Facebook, or even your own Facebook page.
Many people travel for business and want house sitters during the week, as well as week ends. Most of my house sits are for business travelers. So your house sitting on weekends only is limiting you as far as business travelers looking. Are you available to house sit during winter and spring breaks? If so, you should advertise heavily a month or so before the breaks.
If you don't mind me saying, I think your prices are too low. Especially for house sitting. You should do a sitter search in your zip code and try to fall in the middle of the highest and lowest priced sitters. When you are priced low, people tend to not take you seriously and/or you tend to get requests that other sitters turn down for a variety of (not good) reasons.