Attribution is as inscrutable as it is necessary as the path to purchase becomes more of a cross-platform tango. But for agecnies, too, it is a dance among vendors, incomplete data and knowing when not to rely on machines.

New projections see all digital channels growing steadily for much of the decade, although people are shifting habits across and within these channels. The biggest question involves how marketers and media help consumers pull the fragments together.

Cross-channel communication with customers has to be personal or it somehow defeats the purpose of leveraging first party data meaningfully. How do you keep that communication from feeling like an awkward robot valet?.

Marrying the biggest and smallest screens in the home, TV and mobile, is one of the most challenging but ultimately impactful cross-platform synnergy for brand messaging. But it won't be easy.