Trackerlist must evolve along with the tracking methodologies we document, so today we’ve added a new tracking method to Trackerlist: “Personal data matching.” When you see this associated with a tracking company, it means we have determined that the company uses personally identifiable information (like email, name or phone number) to facilitate online tracking. See this example.
How does this work? Typically companies like Datalogix will compile offline transaction data that they can associate with an email address, such as store purchases made with a loyalty card. If the purchase history includes lots of diapers, it might support a profile like “New Parent”, which is useful for targeting ads about baby formula. A website publisher looking for revenue will give Datalogix accesss to email addresses that the publisher gathered from user registrations. When a registered user logs in to the site, the publisher allows Datalogix to drop a cookie that is uniquely keyed to the user’s offline profile. Then as the user visits different websites across the web, that browser is known to Datalogix and its partners as having the “New Parent” profile. The website gets paid for facilitating the match based on the personal registration data.
This targeting technique raises issues beyond those found in traditional anonymous behavioral targeting:
- It involves offline behavioral data, which users don’t yet expect to affect their online experience, and
- It involves the use of personally identifiable data, which increases the risk that specific behavior will be associated with identity.
Because of these concerns, we’re highlighting personal data matching as a special classification in Trackerlist. Publishers and their users should understand more clearly when personal data is being leveraged in this way. This is especially important since, based on our research, a relatively small percentage of sites working with personal data matching companies are actually providing appropriate disclosure in their privacy policies; in fact, many sites where we see these kinds of trackers have literally incorrect policy statements in place. Stay tuned for more details.