Is the Google Cookie Tracking Everyone’s Surfing Habits?

January 30, 2009

Photo: Google Cookie by Massless on Flickr

Google tonight made an important change to the Google Ad Planner that – at least as I read it – means they are now tracking every site you visit via a Google cookie and serving the aggregate data up to advertisers. If I am wrong I hope someone will tell me. (If this post is wrong I will correct it – but this is how I am interpreting what Google has put out there so far.)

Let’s take a look at the facts.

First, Google yesterday made some subtle changes to its privacy policy. Coincidence? Maybe.

Second, according to the Google Adwords blog, the search engine has now added a new site traffic metric in Ad Planner called Unique Visitors (cookies). This, according to Google is a new cookie-based metric that “help(s) you cross
check and compare metrics, similar to Google Analytics unique visitor metrics.”

The help page goes a little bit further, saying that unique visitors (cookies) is “the estimated number of unique cookies on a site. The unique visitors (cookies) metric is more similar to data from server logs, analytics applications, and ad servers.”

Google does not provide any additional details on how they are gathering the data from cookies. Is it possible that this means that as long as you have visited Google once and get cookied that they are now tracking every single site you visit, even if you didn’t get there via a search? It’s unclear. But it sounds like it. I hope they will be more transparent.

However, if this is true, given the huge number of people that have done at least one Google search (e.g. everyone) that sounds like they are collecting a staggering amount of data. And something that might alarm privacy advocates while at the same time creating the largest consumer panel on the web – e.g. everyone, except those who delete their cookies.