I use twitter to track a few local food trucks/restaurants/breweries. They tweet their whereabouts or what they're currently serving. It's a lot faster for me to check twitter than it would be to check each individual webpage.
To give you an example, here are two of the places that I follow:
SuperDeliMart
Maximus Minimus
I suppose if you have a strong repeat customer base you could use twitter to show off new designs, mention sales, etc...