HTML and CSS Reference
Figure 1-6. What the Firefox browser add-on Collusion looks like
As you can see, Collusion shows what sites are sharing information about you as you browse the Web and, what is
more important, how they access each others information. The image in the figure was taken by going to five different
web addresses. It's remarkable to see how much can be collected without a user doing much other than typing in
URL's. An advertiser can see that some publishers are setting cookies on users to track certain information. Then that
information can be sold to make better media buys and/or tailor the creative messaging within the ad itself.
Learn more about Collusion at its web site: www.mozilla.org/en-US/collusion/ .
As you now know, when you use Gmail or Yahoo Mail or something similar, you essentially allow the use of
your information for advertising purposes. Publisher-passed data allows publishers to put an encrypted string
of information into the ad server's ad tag and allows the ad server to determine what viewer it has and craft an
appropriate advertising message. This information could include age, geographic region, zip code, gender, and even
interests among many other inputs.
Say that, from my e-mail and browsing history, Yahoo knows I am 18 years old and interested in electronics. If
an advertiser is promoting new products to me, Yahoo can pass information to the ad server that my known interest
is electronics and that I am 18. The ad server has inputs to determine an accurate output message, perhaps a video