It's OFFICIAL! I'm going to be an LBS owner!

[Torrilin]

Superfeet insoles.

Bungee cargo nets.

Tire pressure gauges that aren't attached to bike pumps.

The little reflector strips for keeping pants legs out of bike chains.

BROOKS!

Stock a cheap commuter bike that's not a piece of crap. Maybe a Redline 925, or used 3 speeds. Something that works well in your area gearing-wise and that can haul a bit and won't need a ton of extras to be a useful bike. If you can commute by bike to the shop, do. Your customers will love your expertise. Also, they'll keep coming in because they need some weird little thingie for commuting and they *know* you can get it for them. Add on sales are your friend.

I'm a commuter/utility biker with one bike. If I call a shop about maintenance, I'll say I've got one bike and ask how we can arrange it so I get my bike back the same day. It's not I need to be first in line or anything; it's I don't have a car. I need my wheels .

Real parking. Y'know, for bikes. All the shops around here do have bike parking, but it's mostly very icky racks that are hard to park at. Can't blame them, the racks all seem to be a good 20 years old . But you're doing a new shop so maybe you can have better designed racks.

One of the shops in town has an air compressor labeled "free air", fitted up for presta and schraeder valves. Very thoughtful. I would spend more money there, but I can never find anyone to take it. So then I end up going to the other bike shop where there is always someone to take my money.

[KnottedYet]

Kona
Surly
Brooks (maybe just a set of saddles for folks to try, and you order the one they want)

TOOLS! Several varieties of tire lever (like the Crank Bros Speedlever) and shapes of Allen wrench (Ts, Ls, foldy-things) Leathermen, pedal wrenches. Pressure gauges. The sorts of thing the average Joe can be told to use or would cheerfully buy so they'll have a spare.

Cold pop. My LBS has a fridge full of canned pop for $1. I'm always surprised by how many cans of pop they sell while I'm there.

Good bike parking.

Clean bathroom.

Classes at the shop.

Rides starting from the shop.

Socks with your logo and shop name on the cuff.