Secondly, other useful information, such as the latest news and latest weather information, might be delivered instead of advertisements at the user's convenience. Suppose that a user obtains an online order form for some goods. The advertising agent can detect this event. It then examines the order form to see what goods the user wants and the price offered. In the Internet, privacy is one of the first issues.
Advertising agents keep their customer's private information, such as age and home address.
Therefore the contract between advertising agents and the customers should include a privacy clause which prohibits the agents from forwarding their private information to advertisers without permission. In this section we describe a simple prototype of our new advertising framework. We use a sightly augmented Web browser which can merge Web pages from different Web servers. Selecting this item, a window is opened and the names of filter programs can be specified. Those filters can be piped in order as illustrated in Figure 4.