"Never stop testing, and your advertising will never stop improving" was said NOT by a modern day marketer but by the godfather of advertising, Mr Oglivy himself. So where do you start to measure marketing success? User Acquisition paper trails us to the solution.
The next time a marketer pushes the concept of using saturated marketing channels like social and search ads, pause and consider these average CTRs (click through rates).
To measure success, Mark Zuckerberg has said to focus on one specific goal and forget everything else. Keep it simple and know what your "big win" would be at every step of your demand generation effort. So what's a "big win KPI" look like?