How Google adverts got personal
Updated on 08 April 2009
Internet search and advertising giant Google today launches a controversial new behavioural targeting system, something it is calling interest-based advertising.
Benjamin Cohen explains how the system works
Google is by far the largest search engine in the UK with around 86 per cent of the market and the company sells advertising relating to the search terms that users enter.
But it also sells advertising for hundreds of thousands of other websites through its Adsense network.
The advertising that users currently see on these sites is based on the content that they are viewing. So a visit to a travel website would likely result in a user seeing adverts for holidays.
The new system monitors all of the visits that a user makes to any of the websites within their network and begins to build a profile of all of the user's interest.
For example, if you often visit cycling or fishing websites, you will start to see adverts for bicycles or fishing rods when you are viewing completely unrelated content.
It is important to note that the Google system will not know your name, or indeed your home address.
Similar systems have been used by other advertising companies for years but the sheer scale that Google offers advertisers makes today's launch a pretty significant event.
By default everyone is opted-in for Google to monitor their visits.
Google argues that consent is given by inertia. In other words, users will not bother to opt-out.
'The ICO will be contacting Google to clarify whether Google adverts will be displaying clear links to both further information on the origin of the advert and to how users can change privacy settings.'Information Commissioner
Users with concerns can visit their ad preference manager to find out the interests that Google has associated with them; they can remove some, add others or perhaps opt-out of the service all together.
But you will need to do this on every computer and web browser that you use at home, work, university or school.
But how will you know if the website that you are visiting is a member of Google's network and therefore that visits to it would be tracked?
Well you could find out if the website has a privacy policy. Google has asked all of its partners to update them to inform users that visits are being tracked.
Or you will much of the time see a very small Google logo above or below the advertising spots.
If you click the logo then you will be taken to a page that then contains another link that will eventually take you to the ad preference manager.
We were told by the information commissioner that Google promised them that its logo and a link for users to opt-out would be on every page that will be tracked.
But, Google told Channel 4 News that it has an "aspiration" to have made this the case by Christmas of this year.
The information commissioner said that in the light of this, they will investigate.
In a statement, it said: "The ICO will be contacting Google to clarify whether Google adverts will be displaying clear links to both further information on the origin of the advert and to how users can change privacy settings."
Privacy campaigners argue that regardless of the information that is provided to users, Google should actively seek our consent rather than simply give us the choice to opt out.
Dr Richard Clayton of the University of Cambridge told Channel 4 News: "It should be an opt-in system, if people know what's being done with their data and if having adverts that are specially targeted for you are such a great thing then wouldn't people be queuing up around the block to sign up?"
"They are doing it as an opt-out because they will make more money, it should be an opt-in," he added.
In a statement to Channel 4 News, Google said: "We believe interest-based advertising will help people see better ads online. We also take privacy very seriously and have built features into the service to protect consumers' privacy.
"Simple tools allow users to edit their own interest categories and choose the ads they'd most like to see. They can also opt-out of receiving interest-based ads altogether."
