Reply to post: So what?

So what?

According to Chiou and Tucker, data retention periods didn't affect the flow of traffic from search engines to downstream websites.

Google doesn't really care about downstream websites. What it is interested in is demonstrating the efficacy of its search algorithm to advertisers and it doesn't look like this was covered in the study. To demonstrate the efficacy of the algorithm it constantly needs to check that the results it provides are indeed what users are looking for and constant perusing of the logs is one of the ways to do this, though I suspect aggregation of search terms is main benefit.

I suspect that Google itself knows the value of the data it collects, including the problems associated with ever bigger haystacks. You can see how they do some of these things with Google Trends or the N-Gram research.Trends allow like-for-like comparisons over time, eg. the much touted early indicators of autumn colds and flu. That's gold dust for some but only makes sense with aggregated, anonymised data. I suspect they would probably already pour cold water on the value of ever greater personalisation of adverts, which is where Facebook seems to be going. I think we're going to find out that influence, the holy grail of advertisers, is best reached by the right combination of adverts and content.