With fast food workers demanding $15 an hour I can see these taking hold real fast. A resturant that employed 80 will now run needing only 8.
Those are (oil)boom town prices, boom town wages, and jacking up the wages elsewhere will only see increases in rent and other costs for the worker as the rest of the labor force clamors for raises. Without something far better paying to drive that (oilfield jobs), it would not fly.
The restaurant which could deliver a good (if somewhat mechanized) burger for less would win.