Only a few midtown Manhattan blocks separate the worldwide headquarters of Omnicom and Interpublic. According to Google Maps, it's just a 12-minute walk.

But the industrial gap their proposed merger will close will make the new-and-improved Omnicom bigger, better and the most-resourced of the major agency holding companies to survive what some see as a looming extinction-level event for the kind of dinosaurs that have historically roamed the streets of Madison Avenue.

Or, as Omnicom's once and future CEO John Wren stated when the deal was announced late last year: "The combination will bring together unmatched talent, services and products, and platforms. Omnicom will have the deepest bench of marketing talent, with over 100,000 practitioners."