Powerful product, country, and functional silos are jeopardizing companies' marketing efforts. Because of silos, firms misallocate resources, send inconsistent messages to the marketplace, and fail to leverage scale economies and successes--all of which can threaten a company's survival. As David Aaker shows in Spanning Silos , the unfettered decentralization that produces silos is no longer feasible in today's marketplace. It's up to chief marketing...