He is the son of Forrest Mars, Sr., and grandson of Frank C. Mars, founders of the American candy company Mars, Incorporated. As a member of the Mars family, his share of the company and other assets were worth US$10 billion in September 2010, making him the 52nd richest person in the world and the 26th richest person in America, according to Forbes. As of October 2012, Mars is listed as the 30th richest person in the world with an estimated net worth of 20.1 billion.
With his two siblings, John Mars owns Mars Inc., the world's second-largest confectionery. The company manufactures candy (M&M's, Milky Way, Snickers), chewing gum (Juicy Fruit, Orbit, Extra), pet chow (Pedigree, Royal Canin, Whiskas) and packaged foods (Uncle Ben's, Suzi Wan). The closely held company has annual revenue of more than $30 billion.
AT 6.30AM SHARP, John Mars pulls his 1989 Jeep station wagon into the small, empty parking lot at 6885 Elm Street, in the Washington suburb of McLean, Virginia. He parks toward the rear of the unadorned, unmarked two-storey brick building. Except for the coffee shop serving breakfast next door, the neighbourhood is quiet.