In my experience, I got a customer the first day, before any shop sections were bought.
I got another customer 2015/07/19 04:30. Sold them plenty of armour. They went questing. They haven't finished their quest since. Several groups have finished/failed their quests, come back to town, shopped, went questining again, and finished/failed their quest again. My group? Still questing. Also, I've had no other customers.
EDIT: All your new parties showed up in the other shops again. Am I doing something wrong that they don't like my shop? I thought a shop sign at the beginning would attract more folks to my shop, but it doesn't seem to have done anything. I've got leather armour, scale armour, chainmail, torches, oil lamps etc.
