A deal of this magnitude will have implications far beyond Omnicom and IPG. Agency heads tell us what they think of the motives – and what it means for them.

Promising to combine two titans’ expertise in media, creative, and digital services, the merger is being touted as a win for clients and shareholders alike. But history and industry insiders suggest caution.

The $13.25 billion acquisition by the ad holding company Omnicom of Interpublic Group has industry insiders speculating about more M&A to come.