I suspect that there was little data to analyze how much attention the ads were commanding back then.

I often think about how so many things now have been optimized (mostly for profit) to the extreme by data-driven processes, with big corporate marketing certainly being one of them.

Up until two or three decades ago, I suspect that it was all based on tradition and the "gut feel" of out-of-touch and arrogant executives talking to each other over drinks (thinking of scenes from Mad Men here).