One of my new year's resolutions is to carve out some time to look at franchising industry trends. The franchising industry is a major sector of the US economy. Depending on the data source, franchises employ between 7-9% of all American private sector workers. It also continues to grow and diversify, with new franchise concepts in a wide variety of industries.
It also is an interesting organizational model, with a central core company and lots of affiliated small businesses. This general type of structure is emerging in many industries - although not with the tight financial and legal requirements of franchising.
The International Franchise Association has a series of reports profiling the changing franchise industry.