The biggest one in marketing is cross-channel attribution and valuing hard-to-measure channels like display, video, etc. Better data lets you avoid wasting dol

The biggest one in marketing is cross-channel attribution and valuing hard-to-measure channels like display, video, etc. Better data lets you avoid wasting dollars and better allocating your budget by properly assigning the weight of how much revenue contribution a given channel/campaign/placement/creative/etc. should receive. This is arguably the toughest problem in the industry, and solutions by Google, Adobe, etc. are just starting to make headway, but are still very expensive and very custom with few exceptions (see the new data-driven attribution release for AdWords for example).