ACME Sprockets: ACME believes that its users should be able to get to their information as quickly as possible. However they want the ability to spotlight certain new areas if they wish. It's a quandary, but they think they've found their solution. They want a "Welcome/What's new" page that the visitor can turn off if they wish. When they hit ACME's site the first time, they see the "welcome" page, and if they check a certain box, they can choose not to see that page ever again. Either way, they can continue on to the rest of the site. When the visitor returns, it goes to the main page, or to the "welcome" page again depending on whether they set the cookie.
Investments R Us: The Info tapes have been doing well for Investments R Us. Then think people would be willing to give them a little information in exchange for the Real Audio samples they've been offering. They want to have visitors fill out a form with some nice demographic info and register for their site. Registered users can keep their username and password stored in a cookie. If they're registered they can get to the audio areas of the site, and the server will keep track of who has visited, how often and what samples they listened to so that Investments can compile some statistics of possible demographics to target.
Blockmonster: They've got their catalog online and they can do transactions on their sites, but they want to do more "selling." So Blockmonster is looking to create a cookie-based "suggestion" system. They'll put together a database that links artists with "similar artists." When a visitor goes to a page on the Blockmonster site about one band, the page will also suggest other artists that might like (all of this would link into their review database as well.) Meanwhile, a cookie would be set that would store information about which artists/genres the visitor was interested in. When the visitor returns to the site the cookie would be read and a listing of appropriate sales or specials would be presented to the visitor.