You don't mention whether or not you were logged into Amazon at the time and left out some important details about your personal situation with your computer but it ultimately doesn't matter. You've brought up an important topic.
As you've discovered, it becoming increasingly difficult to preserve your privacy online. This can only be accomplished, if it can be accomplished at all if people proactively take steps to prevent tracking.
Most average people I talk to are completely oblivious to the fact that tracking is going on at all and would be astonished to learn how rampant it is and what lengths corporations are going to to identify
individual users and invade your privacy. Some people are vaguely aware of tracking and they know a little about cookies but don't give the matter much thought. Any given commercial web page can have literally dozens of tracking schemes in play all at once not including cookies!
It is very good that you are being careful about
Local Shared Objects (LSOs). If you are not already using it, the browser plug-in
BetterPrivacy is vital in this regard. It will make managing this problem much easier.
Check out
Ghostery , a browser plug-in that enables its users to easily detect and control
web bugs, that are objects embedded in a web page, invisible to the user, that allow the collection of data on the user's browsing habits. You can download it
here.
One vital tool is
NoScript an extension that provides important security as well as privacy protection. Many would be amazed to learn about how many individual scripts are running on most web pages they visit. While some of these scripts just enable certain functionalities, many serve tracking and other unwelcomed purposes.
Another important privacy add-on for Firefox and other browsers is
Adblock Plus that provides filters for various embedded elements that are designed to feed you ads based on your habits and other insidious stuff like collecting information about your individual browsing habits and preferences.
An even scarier tracking method that has been under the radar for sometime now is called
Browser Fingerprinting that can identify your unique web browser
without cookies. Check out
Panopticlick from The Electronic Frontier Foundation (EFF) to learn more about this and to check your computer's uniqueness. If you've never heard of Browser Fingerprinting start by
reading this article in PC World. (This is an older article written before fingerprinting became as wide spread as it now appears to be.)
Another consideration is whether you have a Static (fixed) IP address usually found on cable systems or a Dynamic IP address (changes when you disconnect and reconnect) typical of dial-up or DSL. Obviously if you always have the same IP address all the time, your computer will always be identifiable.
Finally, the New York Times published a good article a few weeks ago titled,
How to Muddy Your Tracks on the Internet - well worth reading.
This is a huge, important topic that is only touched on here and deserves wider attention. Thanks, orbital for posting about it.