Personalization is hot these days, widely seen (   ) as a key battleground in the battle between Microsoft, Yahoo, and Google. But what is personalization?
I'd define web personalization as delivering different and unique content to each individual customer based on the customer's interests. It's your own version of the web site, a site just for you.
To distinguish personalization and customization, I would argue that personalization uses implicit interests and customization uses explicit interests. Personalization learns what you like from your actions; you are what you click on and what you buy. Customization requires you to explicitly specify what you want; you are what you say you are. My Yahoo is an example of customization. You tell the site what you want. Amazon.com is an example of personalization. The site learns your interests and adapts.
In a world with a glut of information, personalization offers a way to find focus. It doesn't waste your time showing you what everyone else sees. It learns what you like, shows you what you want to see, and filters out the rest. That's personalization.