Before I go any further, I have to say it up front, whatever else may be wrong with the changes to the Google Privacy Policies, one thing should be clear – advertisers are not getting their dirty mitts on your personal data.

Others have explained the wording of the policy more eloquently than I – I’d refer you to this Marketing Land post – but it is clear that trusted news sites like the BBC, the Guardian and Sky News are misrepresenting the facts.

Everyone seems to have their knickers in a twist about your personal and search information being sold to advertisers. Understandably so, but this is not what happens.

As an advertiser, I can indeed choose to target people by demographics (age, gender) or by their interests (motorbikes, movies) – or even a combination of the two. But that information does not – and will not – come from you explicitly telling Google all about yourself.

Google uses a DoubleClick cookie (a snippet of text on your browser) to track your web history to figure out who you are and what you like.

For example, I like to cook, so I regularly visit sites that are all about cooking like Nigella.com and Delicious Magazine. Google would associate a specific demographic (I’d image females, 25 – 34) to those sites and based on the fact that I visit them a lot, they might decide that I am a 25 – 34 year old female and record that information in the DoubleClick cookie on my browser.

It’s an extension of what’s been happening offline for years – publications build up information about their audience to attract advertisers. And no one seems to mind too much that Facebook has offered advertisers the ability to target users by gender, age and even birthday for years. Arguably Facebook’s advertising platform is more intrusive than anything Google has to offer – and unlike Google, Facebook does not allow you to opt out of personalised advertising.

You can find out exactly what demographic and interest groups Google has placed you in and opt out of receiving ads based on this data through their Ad Preferences Manager.

Still concerned about your privacy?

Let me show you some of my data:

I am a 26 year old female. Google knows this about me, they tell me so when I look at my profile information for YouTube:

YouTube stats - gender, female - age, 26

And yet, when I look at my Ad Preferences data about my demographics, look at what I find:

Ad preferences date - gender, male - age, 35 - 44

That’s right, based on my browser history Google thinks I am a 35-44 year old man. Thanks Google.

Now arguably the data sharing exercise takes place today so this demographic data may change, and yet the DoubleClick cookie is inferring my demographic information based on the websites that I have visited, not on the personal information I give them. Clearly the kind of sites that I visit suggest to Google that I am much older and more manly than I actually am.

It is true that data sharing may help Google to fine tune their demographics information and more accurately suggest the audience of a website. And yet their data will still be generalised and non-personally identifiable, meaning there will always be these inaccuracies. If I continue to visit the type of sites that Google continues to believe attract men older than I, I will still be classed as an older man – and advertisers will continue to target me as such.

Key takeaways for anyone with concerns

  1. You can easily opt out of demographic targeting. If you don’t want advertisers to be able to target you based on who you are, you can withhold the information.
  2. Google is not selling your personal or search data to advertisers. The closest they will come is being more accurate in their estimations of the demographics of a given website.
  3. This is nothing new. Advertisers have been collecting data about you for years and Facebook offers access to more sophisticated targeting options.