The franchise and the virus work on the same principle, what thrives in one place will thrive in another. You just have to find a sufficiently virulent business plan, condense it into a three-ring binder ― its DNA ― Xerox it, and embed it in the fertile line of a well-traveled highway, preferably one with a left turn lane. Then the growth will expand until it runs up against its property lines.
"Snow Crash". Book by Neal Stephenson, 1992.