Poor design in a web page or an application can be expensive in a number of ways.  A frustrated web user simply goes to your competitor's site in hopes of finding it easier to use. Application users will need to contact your support department, costing your employees time as well as sacrificing client satisfaction.

A highly useable interface becomes invisible to the user.  It is a tool to solve a problem, not a problem itself.

Consider this Order Search page from our hypothetical company Zynoon.   At first glance Zynoon's Order Search page looks as though it may be the "After" page instead of the "Before" page but in fact there are a number of problems with this page.