This document discusses how blockchain technologies can benefit marketing and advertising. It provides examples of how blockchain is being used to address issues with digital advertising fraud and transparency. One collaboration uses blockchain to reduce reconciliation times and provide closer to real-time campaign data. Another partners media companies with IBM's blockchain to increase financial transparency in media buying. A third case discusses American Express using Hyperledger's blockchain to make its loyalty program more flexible by allowing merchants more control over rewards offers. The document promotes blockchain as a way to increase trust and market opportunities for marketers.