You nailed it. These days, a store hast to have a specific service, or be a speciality store to survive... This saddens me, I practically grew up working in a mom and pop, and then worked in the "pet industry" after that...
Down South: just remember that PetCo's Smarts, PetLands, ETC will run schematics on areas, so if your town is up and coming... then there is a good chance that one of the Box chains will have an eye on the location. My best advice, be original with an educated staff... that will be your best defence. Because, unfourtantly, you can't beat a Box Chain's prices. Just sad truth...