From the article: Customers can thank Boston Market—which opened its first store in 1985 in Newton, Mass., under the name Boston Chicken—for the modern rotisserie chicken industry.

This was a surprise to me. In Italy "Rotisserie chicken" have been a common urban offering since at least the '60s, probably even before. No idea about other parts of Europe or the rest of the world, but I distinctly remember small stores displaying roasted chickens since my childhood.

The only recent innovation is that you can now find these in larger supermarkets and that most of the stores are now managed as some franchise.