For those of you in this thread that are dismayed that some of us don't enjoy being tracked, I highly recommend a short, entertaining documentary that's currently available on Netflix, iTunes, etc. called:
Terms and Conditions May Apply
http://www.rottentomatoes.com/m/terms_and_conditions_may_app...
Actually, I think even some privacy-conscious folks might learn a thing or two from it as well. I know I did. :)