The Tempe Food Court is a really cool example of one that leverages real estate to create a ghost kitchen space for multiple brands in one building without having to allocate space for dining in. Buying an existing building in a relatively metropolitan location and retrofitting the space to accommodate multiple brands is certainly growing fast. If you look into the Tempe Food Court, you'll see they not only focused on a good building setup but also location and where they see a large demographic of people who order take-out. The trend is certainly not dying out any time soon.

I own a small chain of frozen yogurt shops. We're independent (not franchised) so we have control over all brand/marketing/menu/supply chain decisions. I'd say we're a lot closer to retail than a restaurant, since all our employees have production responsibilities. Frankly it's a business that can cash flow very well when everything is hitting, but it takes a lot of presence and patience to keep things running smoothly and the exit opportunities aren't great unless you get fairly large. I imagine that dynamic scares a lot of people off.