"Because psychology often does not meet the five basic requirements for a field to be considered scientifically rigorous: clearly defined terminology, quantifiability, highly controlled experimental conditions, reproducibility and, finally, predictability and testability."
Predictability and testability being the big problems. Science is prediction, not explanation. Psychology has a huge replication problem.
Advertising, though, has become a science. Predictability, testability, controlled experimental conditions, quantifiability - that's Google's business.