Privacy on the Web, Part 1: The Beacons Know You

by Steven McElwee, CISSP

Did you ever notice how a web site you have never visited before knows your interests enough to give you targeted advertisements? Sometimes, the ads are based on the content of the site, but other times, there appears to be no connection. There is an approach to collecting user information that crosses web site boundaries and maintains a history of your preferences.

You may ask, how is this possible? Are these companies sharing information? Is there adware on my computer that's giving out this information? No. The answer is much simpler -- outsourced advertising and analytics.

Many companies can't afford to maintain a department that attracts advertisers, manages advertising sales, and tracks ad performance. As a result, they outsource their advertising to a specialized company. In the same way, most companies do not have the tools or expertise to track their own web site metrics, so they outsource to large companies that specialize in web analytics.

To display appropriate advertising, track ad performance, and track overall behavioral metrics on web sites, these companies that provide the service require the publisher or advertiser to put a small piece of code on their web site. This may be a small piece of Javascript or a simple image request. It is this image request that allows the advertising or analytics company to track user behavior across multiple web sites, since they are provided information about you at each site that has their beacon.

This week's posts will describe web beacons and your privacy in more detail. They will explain:

• How Beacons Work
• Analytics, Recommendations, Summarizing, and Anonymity
• How to Hide from Web Beacons

Now that you know, do you mind that these companies can track your behavior across web sites? Post your comments below.