You will see these in large use in asia, especially Japan.

It would be really awesome to see one in OKC, but downtown would probably be a better place to see it. Or near a large university. I always assumed they made money by having a really high volume of customers, which this type of establisment can easly feed. Really would not work well with the limited traffic of plaza. A restraunt would do well, but not a automat designed to feed tons of people in the shortest amount of time.

You can read more about why they started to shut down here.