Is there a multiple small-cart business model?

Beautiful espresso cart by @Delapazcoffee at brunch today!

San Francisco’s AQ restaurant Twitter stream

De La Paz at AQ Restaurant in San Francisco
De La Paz at AQ Restaurant in San Francisco (photo by AQ Restaurant)

I can’t be the first person to think of this but something about the combination of the above quoted tweet and its accomponying photo got me thinking: is there a business model for a little collection of small coffee carts that contract out with a rotating roster of local restaurants to offer in-house coffee service during breakfast and brunch (I figure those would be the most popular). Is this what De La Paz is doing with their one cart already?

My thought is that in coffee-appreciating cities, the service could be a marketing bonus for a restaurant’s meal service on the days the carts appear, with the word being spread via social media and the restaurant’s in-house signage. If the carts are owned and operated by a particular roaster, or even if they aren’t but the cart is a wholesale account of a particular roaster, further marketing kung-fu could be worked by advertising the schedule for the cart appearences, inside the roaster’s store(s).

There must be some conflicts I’m not thinking about here.

What do you think?