Even though I'm looking at sitters in my zip code, the message shows, "too far away for sitter"; why?

Sitter's can make their service radius as small as they want (like 1 mi) which is way smaller than a zipcode. If you're looking for someone to do drop-ins or walks it takes a lot of additional time if a lot of driving is required. I would expect there to be some sitters in your area though, maybe someone else has some ideas?