Google DoubleClick appears more frequently than any other name in our Tracking the Trackers database. Here, we learn as much as we can about what it does.

Google Doubleclick : What is it?

Doubleclick is a business owned by Google that makes it money from online advertisers and publishers. This is done by:

Ad-serving
Online publishers use Doubleclick to display adverts on their websites.

Ad delivery
Doubleclick will let advertisers control how often an ad is shown to a browser, how long it is shown for and how often it will appear.

Behavioural targeting
This comes in two categories:

Targeting for one website owner: An online publisher can set a Doubleclick cookie to tell them what sections of their sites you are browsing. Doubleclick will then judge the type of adverts you might like to see from what you’re browsing. For example, if you are on a news website and you visit the sports pages, then adverts for match tickets may be more relevant than makeup. This information belongs to the website owner only.

Targeting in advertising networks: Google runs a service called Adsense, in which lots of different publishers pool the information they get on browsers. This helps them build up a better idea of the type of adverts someone might want to see. This is a third-party advertising cookie.

Who makes use of Doubleclick?

Any web publishers can use Doubleclick, as long as they meet the company’s terms and conditions. Google also uses Doubleclick across its own sites.

Doubleclick tracks what kinds of information?

In their privacy policy, Google explains how data is recorded from a generic Doubleclick cookie. It looks like this:

In Simple Terms:
DoubleClick empowers publishers to display ads effectively. Advertisers use it to fine-tune how their ads are presented, ensuring a more personalized and efficient advertising experience for users. Google employs DoubleClick not only for its own sites but also to enhance ad delivery and targeting capabilities across the digital landscape.

This information provides details about an ad interaction on DoubleClick:

1. Time and Date:

• Timestamp indicating when the ad was viewed (August 6, 2010, 12:01:32).

1. Ad Placement Information:

• ad_placement_id: Identifies where the ad was displayed on the site (ID: 555).
• ad_id: Represents the unique ID of the specific ad viewed (ID: 1005).

1. User Information:

• userid: A unique ID assigned by a cookie to your browser (0000000000000001).

1. User’s Location:

• client_ip: Records the user’s IP address (123.45.67.89).
• referral_url: Specifies the page you were on when viewing the ad (http://youtube.com/categories).

Implications:

• DoubleClick uses this data to track the time, user, and ad details for analytics.
• The userid allows DoubleClick to associate ad views with specific users.
• Advertisers can gauge the effectiveness of ad placements (ad_placement_id).
• The referral_url reveals the context of ad views, such as being on YouTube’s categories page.

IP Address and Location:

• DoubleClick, by recording the IP address, can estimate the user’s country and town/city.

Note:

• While this data aids in ad targeting and analytics, it also raises privacy considerations due to the tracking of user-specific information.

How is this information used?

On its own, this data can tell Doubleclick how many times you have seen an ad and, for example, whether you need to see the UK or US version. It cannot find out any personal information about you.

If the cookie is set on an website that is part of AdSense and then you browse another site using AdSense, the the same information will be recorded and pooled. Over time, guesses can be made about the interests of the person using that browser – whether they like football or ballet, for example, or if they visit Marks & Spencers more than Tesco..

If enough browsers display similar patterns, they become part of a “segment” labelled something like “football lovers”, “fine food lovers”, “current affairs enthusiasts”, etc – these become labels that Doubleclick lets advertisers choose from when they select the types of people they want to see their ads.

Once Doubleclick have an idea about the interests of the person using the browser, they will try to use them to infer how old you are and whether you are male or female (again, to put you in a segment).

To check what segments Doubleclick has you in, go to Google’s ad preferences manager (you don’t have to be signed in to Google).

Even if Doubleclick is used to serve adverts, Google says there are some websites where segments won’t be created: for example, health websites (where there is a risk of building up a profile of a medical condition) and political websites (where they might build up a picture of a political affiliation).

How much money does Doubleclick make?

Google bought DoubleClick for $3.1bn in 2008; since then its financials are combined with other parts of Google.
Google currently generates 96% of its revenue through its advertising products.
In 2011, it saw advertising revenues of $36.5bn, with $10.4bn coming from non-Google sites in its ad network.

Is the data sold to third parties?

Google says it is not sold to third parties. When the service is being used by a publisher for its own purposes (not in an ad network), the publisher owns that data, not Doubleclick.

If data has not been sold on, has it been given to or shared free of charge with third parties?
Not directly. However, the Doubleclick platform is a charged-for product and the use of segments is part of the appeal for advertisers. While they are never given information about individual browsers, they do benefit from all the data in an aggregated form.

How long is the data stored for on the user’s browser and on Doubleclick’s servers?

Doubleclick cookies on the browser are set to expire after a number of years (we have seen dates in 2014 for these). However, the override for this is clearing cookies.
Newer cookies “60 days in market” and “30 days in market” are actually more valuable to advertisers as they give a better indication of what the person using that browser is interested in right now.
IP addresses are anonymised after nine months and the data in cookies is anonymised after 18 months. At this point they are not used.

What evidence is there that Google Doubleclick deletes the data?

A tricky question to answer, but when it comes to the cookie on your browser, Google says if you opt out from receiving Doubleclick cookies and visit its ad preferences manager, it will recognise your opt-out status.

Is the data ever matched to personally identifiable information?

Never, says Google. This would be a breach of Doubleclick’s terms and conditions. The information obtained from the cookies is also never combined with information that Google obtains from its other products and services. You browsing behaviour will never be linked to your Gmail account, for example.

What other ways does it track?

In addition to its Doubleclick cookies, Google says that if you click on an advert a cookie will be set on your browser. This is designed so that the company that advertised will know if you then, after seeing an advert, went on to buy the product.

When a cookie isn’t available, Google say it may use “anonymous identifiers” instead. This may happen if you access a site from a mobile, for example. One such “anonymous identifier” would be Doubleclick recognising the unique ID of your phone or tablet and assigning you an ID. Googe’s privacy policy gives instructions on how to manage this process.

Do the cookies circumvent privacy-enhancing software?

No special effort is put into circumnavigating tools that are designed to block cookies from working, says Google.

Can Google give one example of how tracking genuinely benefits the people being tracked?

The case from Google
Short-term benefits:
 Relevancy (Before cookies the web was much worse at distributing adverts that had absolutely no relevance or interest to the people browsing. It still isn’t an exact science but they say it’s hard to argue with the evidence that ads that use targeting are more likely to be clicked on.)
 Frequency capping (Cookies can control how often a browser sees the same advert, so browsers don’t get pushed the same advert continuously.)
 Control (Unlike other forms of tracking, such as digital fingerprinting, cookies provide ways for savvy web users to control and block particular advertisers.)

Long-term benefit: it helps pay for the content you read on the web.

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