The End of Cookie Tracking?

September 8th, 2008 by Peter Glaeser | RSS feed for comments on this post | TrackBack URI

Concerns about data protection have inspired publishers of web browsers to come up with “stealth” modes. Especially traditional browser cookies are under attack now. Today a large percentage of the online advertising business is based on these cookies. What are the implications?

Internet Explorer

The current version 7 of IE blocks all third-party cookies by default. That means that pages loaded via frames cannot drop cookies at all if their domains are not equipped with a proper P3P policy. Many advertisers haven’t taken care of that, so all the iFrame affiliates will have more and more difficulties.

Internet Explorer 8 is going to introduce a private browsing mode. Cookies are not rejected right away but are treated as session cookies and deleted when the user closes the browser window. Some people refer to it as the “porn mode” but it was originally designed for the use of the internet on somebody else’s machine. Another new feature is giving users the ability to delete all cookies except those of bookmarked websites.

Mozilla Firefox

The current Firefox does not block third-party cookies. But it’s very easy to tell the browser to delete all cookies on closure. And a lot of people actually do this. Also, there are many plugins that filter out banners and cookies today already. The funny thing is that sometimes these impressions are still counted by the delivering ad networks even though nothing is being displayed.

Google Chrome

This sucker is quite ironic. It allows users to switch to a “stealth” mode making it difficult for ad networks to re-target ads and track conversions. However, the browser software itself collects data and passes it back to Google. As a result Chrome only allows Google ads to work, the other ad networks can be blocked. In my mind Chrome is the biggest spyware ever, nicely packaged I have to admit. I hope they’ll get sued over this.

Solution for Online Advertising Networks

For many years the effect of rejected/deleted cookies has been unkown. Now we finally have a profound data basis. AffiliateFuture, an affiliate network based in the UK, observed a 7% increase in tracked conversions after they introduced flash cookies. I think with the introduction of new browser generations the effect will be much higher.

Online advertising networks can’t rely on traditional browser cookies alone anymore. They must also incorporate technologies such as finger-print tracking and the use of flash cookies. Not one of these methods alone will work. They have to be used simultaneously.

Mobile Tracking

A lot of browsers on mobile phones do not support cookies, Javascript and Flash. So none of these methods can be used to track well on the mobile internet. That’s why for example Google’s conversion tracking is useless for mobile ad campaigns. The way to go on mobile is server tracking on the side of the advertiser and batch imports to the ad network.