What are some little known facts about McDonald's?:

McDonald's ran the McDonalds out of business.

The restaurant was founded by Dick and Mac McDonald. Their simple menu and assembly-line efficiency soon attracted the attention of milkshake machine salesman Ray Kroc. He asked Dick and Mac to hire him as their franchise agent in 1955: in exchange for licensing the name to him, the brothers would get a percentage of sales.

It was a massively profitable arrangement all around. With Ray Kroc opening franchises across the country, McDonald's became the most successful fast food operation in the world.
In 1961, Ray Kroc bought the company and exclusive rights to the McDonald's name from the McDonald brothers, who asked for $2.7 million and the right to control their original restaurant, which they renamed "The Big M", having sold "McDonald's" to Kroc.

Perhaps smarting from the high price, Kroc opened up a McDonald's right across the street from The Big M and ran the McDonald brothers out of business in six months.

Ruthless is perhaps not too strong an adjective to describe the guy who once said, "I’m the old-fashioned guy in competition — I’ll kill the son of a bitch."