Sure, the “tracking technology” is really simple – you drop a cookie with a unique identifier, and you log every piece of information you’re given access to. It’s not rocket science. It can be, however, reasonably invasive. Remember that the primary reason we have privacy policies in the first place is because of the lawsuit against DoubleClick.

The technology is easy, but it doesn’t allow time travel. As I pointed out, DoubleClick has been doing this for a long time, and buying them was the only way for Google to get access to that data. This is a possible explanation for why they were willing to pony up $3.1 billion in cash, not stock, for technology that they could have undoubtedly built for significantly cheaper. Historical profiling data is also, as far as I can tell, the only asset that DoubleClick has which has value to Google (which is in that business) but which does not have value to Microsoft (which is not in that business) – and that’s a possible reason why Microsoft didn’t match Google’s offer.

Please keep in mind the title of your post was “Google has just bought a lot of browsing history of the internet”, not “Google has just bought access to a lot of user activity on the internet”.

I don’t think anyone would argue that DoubleClick gives them access to more data, however, the ‘dirty little secret’ is that the technology to ‘track’ users (look out, they’re behind you!) is so trivial to develop that Google has had DoubleClick’s ‘tracking’ technology and then some for several years at least. Google bought them to keep MS or Yahoo from getting them, and, in a distant second, to learn what DoubleClick knows about display ads.

“Microsoft contends that the $3.1 billion deal, announced on Friday, would hurt competition in the fast-growing market for advertising on the Web and raises questions about how much personal information would be collected by Google, already a dominant player in online advertising.”

Microsoft, in arguably the best position of any company to spy on billions of people if they wanted to, is publicly worried about Google’s potential to “observe and capture consumer information on an unprecedented scale.” Does that make you feel better?

Maybe I’m wrong. Maybe it’s all really just about keeping DoubleClick out of the hands of a competitor. Personally, if I worked at Google, I’m sure if I put my mind to it I could find all sorts of useful things to do with that data combined with Google’s computing cluster. It’s pretty clear that they’re building a predictive model of internet traffic. That’s what adaptive ads are all about – figuring out what people are going to click on before you show it to them. It seems like the more data you have the better that model is going to be, whether it’s old or not.

But the reality is that I don’t know what they might be doing with it. I’ve just gotten in the habit of pointing out the non-obvious side effects of their public actions, of which there are many.

I would be very interested to understand how data older than about 1 year (feel free to use 2 if that makes it easier) is of interest to Google.