What is the difference between a creative agency and a marketing agency?

A marketing agency optimizes distribution: media, channels, budgets, conversion. A creative agency builds the thing worth distributing: the positioning, the story, the identity, the website. Most companies need both, and trouble starts when the two live in separate shops with separate incentives. Watson keeps them in the same room. The strategy that shapes the brand also shapes the media plan, so the message does not fracture between the people who made it and the people who run it.