In my little NH town
there are no interstates or majur highways nearby. No malls, etc. No Wally World; nearest is a 30 min. drive. There are two gunshops: the oldest is almost a hobby for the owner, and is open Th-F noon to 1600, Sat 10-5, Sun noon-1400. He's a good guy, but he's never open when I need something and can get to his shop, even though it's under half a mile from me. Has mostly commercial guns, antiques, and high-grade milsurp. He has reloading supplies in a limited selection. This would get me by OK if it were more convenient.
The newer one, open about a year, is heavy on the milsurp side but has gradually been expanding its spectrum and picking up some very nice top-end milsurp, e.g. match M1/M1A, and a good selection of used commercial stuff. Open regular hours, good prices, and that's where I do most of my buying. He knows his customers by name, and knows what they like, and will often call my office or stop by to let me know when something up my alley comes in. Whenever I buy something, he looks at the sticker and says "ah, just give me XX", always a few bucks off. I keep coming back. I only wish he had reloading supplies; then I'd go nowhere else. He does order bulk bullets for me though.
Either way, I do my best to get all my stuff from these two. Prices are higher than out of town, but I want to keep local gunshops in business.
So Tam, if it's a small shop you're talking about, I think the basics are: reliable hours, a small but representative selection of the basic categories (defense guns, target guns, milsurp, hunting, maybe collectibles), some basic reloading suplies (bullets, powder, primers, brass, tools, manuals) for the most common calibers (45ACP, 9mm, .30-'06, .38spl, .308, .270, maybe .44 mag, .40 S&W, .357), maybe some bulk ammo deals in common calibers (the new guy here always has some sort of milsurp M2 Ball and 7.62 NATO, .223, 9mm, .45ACP), cleaning stuff for common calibers. And a place to hang out; one place has an old church pew with a rough table and mags/catalogs, doesn't take up much space. Access-prompt access- to good gunsmithing. And get to know your customers well.
Things ARE tough; my disposable income is tight these days and I can't buy much in the way of new guns, but I always need ammo/reloading supplies/cleaning supplies. I think you have to have enough of the small, consumable stuff to keep 'em coming. Kinda like milk, bread, beer, eggs for a grocery.