Since blockchain technology allows for the distribution of autonomous parties or people to still work together, I see blockchain as a vehicle for collaboration between different marketing entities working for the same organization or on the same project.
You can think of it as another form of workflow and metrics tracker. As an example, imagine a SaaS company outsources content creation for their blog to an outside agency, writes whitepapers and ebooks in house, and contracts their social media promotion to a single freelancer.
Blockchain can integrate with marketing software used by each of these three entities to track their KPIs, while simultaneously keeping hold of their data in one network. With the help of machine learning/artificial intelligence, it may analyze these different metrics and find correlations, such as leads from Facebook ads being more likely to download a new whitepaper than email subscribers.
And of course, payments can be sent via the same blockchain for services rendered, plus allow for built-in performance kickers and bonuses.
For more on the supply chain implications, see "Blockchain Technology is the Antidote to the Bullwhip Effect."