A donnybrook has developed in the robust subcompact segment of the U.S. market between Chevrolet Sonic and Ford Fiesta, and Sonic is winning this round big-time.

After GM drew attention Tuesday for its decision to ax its $10 million Facebook ad budget, Ford pointed out that it's sticking by its commitment to the world's largest social network.

Three years ago, Ford stole a march on the automotive and marketing worlds by launching its new Fiesta subcompact into the North American market not with a 60-second TV commercial, or two-page color spreads in major consumer magazines, or even with blazing billboards that no one could miss.

Mazda, Ford, Levi’s, and others reveal case studies.