At first, I was shocked that your House Sitting rate was so low (at 20 it's just within a few dollars of your walking/drop in rate) for a full day of care. Then I looked up House Sitters in Chicago, which yielded over 100 pages (over 2000 people available- oh!)When I filtered that to no more than $20, the results were a more manageable 5 pages (page 5 only had 13 listed - so 93 sitters competing at that price point in the general Chicago area- which may be much expanded past your actual neighborhood). When I narrowed it down, to your neighborhood section below $20, you were on the first page for house sitting, dog drop in visits, and walks. It looks like other than the following suggestions below, you might pick up more business by promoting beyond the .com Carry & distribute business cards to anyone who has a pet, whose path crosses yours.
I noticed your profile only has two photos of what appears to be the same dog. I'd suggest you add more dog photos that you've cared for (whether it was a client's, friend's or family's dog)
Also, on the rates, I saw you offer a free bath. That would be worth mentioning as a bonus in the profile (maybe around the section where you talk about you like to take dogs outside on activities, beyond walks.