Good information architecture enables people to find and do what they came for. Great information architecture takes find out of the equation: the site behaves as the visitor expects. Poor or missing information architecture neuters content, design, and programming and devalues the site for its owners as well as the audience it was created to serve. It’s like a film with no director. The actors may be good, the sets may be lovely, but audiences will leave soon after the opening credits.
Jeffrey Zeldman