If you cookie your visitors, you can serve them different features each time they return to your site.
Web usability can be broken down into four objectives and goals (adapted from Jeffrey Rubin's Handbook of Usability Testing):
Is it useful? A site is useful if its design allows users to achieve their goals, whether it's shopping for the first Harry Potter book or comparing two cars to see which one has the better features.
Is it effective? How quickly did you find the Harry Potter book? Did you run into any errors while trying to accomplish the car comparison? Did the site give you additional helpful information?
Is it learnable? Can a new user come to your site and, within a few minutes, learn the navigation? How much effort is needed to acquire competence on the site?
What's your gut reaction? Will users like it and perceive it to be helpful?
Hopefully, those tips will help you improve your Website. December's column will discuss both informal and formal usability testing and how it can make your site more usable.