In the 1950s, and much more recently, the ad industry had to make guesses, based on very limited data, about who was seeing what ads on broadcast media. Sure, t

In the 1950s, and much more recently, the ad industry had to make guesses, based on very limited data, about who was seeing what ads on broadcast media. Sure, the ads for auto batteries and tires ran with football games, not with soap operas. But compared to what you can do with on-line media, they were working in the dark.