A few days ago, all AdSense publishers were presented with a new set of terms and conditions. If you don’t agree with the new terms, you’ll be booted out of the AdSense program at the end of May.
Most AdSense publishers are familiar with cookies, but the term web beacon may be new to you. A web beacon is also known as a “tracking pixel” — a small (usually 1 pixel high by 1 pixel wide) image that is inserted into the background of a web page. The beacon is the same color as the background (or is transparent) and hence invisible to the user. When the browser fetches the image, however, a web server can track some basic information about the user (IP address, any cookies, browser used, etc.). Beacons are generally used in HTML emails to track when and how many emails are read as part of an email broadcast.