Marketing accountability is essential for sustained organic growth, but the challenges to it loom large. The major steps in truly accountable marketing include defining the right results, using the right metrics and finally acting upon the collected insights. To identify the right metrics one has to start with defining the right results: What is the informed decision that needs to be made? But getting data-based answers to key questions is only half the battle. Actually acting upon it is the other half, and often companies are reluctant to change. To create momentum, marketing and finance need to pull together, and the selected metrics need to be useful to both mind-sets. Other proven ways to overcome resistance to data-based recommendations include moving to the proposed optimal allocation gradually and demonstrating the real-word gains through field experiments. When companies succeed in establishing truly accountable marketing, they improve and simplify recurring and quantifiable decisions, which leaves them more time to scan the environment for new opportunities and allows them to take smarter risks.