I don't prefer fast food as my lunch choice, but if they are located at the corner when my stomach says "eat", it will most likely be where I stop.

Kind of the same thing when shopping for marine products. If something breaks at a regatta, and a chain store is nearby, they'll be taking my cash for replacement parts.

I will give Kudos to Rick Bliss, who used to have the "N20 Store On Wheels" at select events (Tybee 500), and the convenience, expertise, and pricing were outstanding and worth any margin he wished to charge.