For all of its existence, up until a year ago, the Masters had only two sponsors: Cadillac and Traveler's Insurance (now Citigroup). The total commercial time alloted to these two sponsors was/is 4 minutes per hour. Now they have IBM, Coca Cola and Citigroup. I don't know what happened to Cadillac.
I once walked next to the sponsors and players parking lot. There must have been 1,000 Cadillacs.