What magic data is there? As I said, there are privacy concerns which are already limiting the quality/quantity of data available and leading to more generic ads. Outside of that, it takes ever more data and the required storage, processing and algorithms to derive exactly what your intent is.

You can look at any algorithm problem and see the decreasing returns (netflix recommendations are a good example). This industry is not full of idiots, there are thousands of data scientists and researchers working on this. If it was that easy, it would already be done.