King Camp Gillette had a partner in the production and marketing of safety razors - Gillette was the idea man and his partner made it possible by devising a way of sharpening a ribbon of steel cheaply enough for it to be profitable. Between the two of them they created an empire that is still the owner of one of the world's most successful brands, which raises the question, "Why Gillette? Why not 'Gillette and That Other Guy?'"
Branding is why - Gillette's partner was born with the wrong name. His name was William Nickerson and, while that kind of ironic self-promotion is en vogue at the moment, it would have been an unqualified disaster in the early 20th century; no jingle in the world would make up for a coincidence like that.