Information architecture is both an art and a science. It begins with a clear grasp of the target audience and their interests and results in the web-like ordering and naming of content elements that will help people effectively fulfill their information needs. To a large degree, the success of your web application is closely tied to the effectiveness of your information architecture in organizing to reflect your audience's interests.
Good information architecture:
Flaws in information architecture can affect a web site's bottom-line dramatically.
Good Internet architecture is like good building architecture: Both add to the value of the property.