Those data are not worthless. They were just difficult to collect and store for analysis. The value was there already - and there were already approaches to collect them (ask Nielsen...), but it was unfeasible to collect them easily and at a very low cost. Google didn't invent people and market analytics, just was able to up it to a scale never seen before. Just like radio/television ads were more effective because you couldn't skip them as you can do on a printed page. New media that allows for better exploiting of old techniques.
Worstall has just published an article were people working for a credit card processing companies were able to "beat the market" because they were in a unique position to collect easily those data and across different customers. And that was illegal because it was insider trading. Google was able to put itself in a position to collect those data easily and across domains, and exactly because it's in that position, rules about how to handle personal data has to be created and followed.
Biting the hand that feeds IT
