Web Beacons - How they work
A web beacon is typically a hidden image (usually 1x1 pixels) placed on a website to capture customer data. It allows the site to capture the actions of the user, as they process pages on a site containing the beacon. Most sites use beacons responsibly to capture general marketing or site visitation statistics. Still, on a questionable site there is always the opportunity for someone to misue this information.
What are Web Beacons?
Why are they invisible images?
How do Web Beacons work?
Why do websites use Web Beacons?
Can I opt out of Web Beacons?