Website usability is something that is often overlooked. Sure, your site might look cool, but can visitors find what they want, when they want it? Is it easy for them to use, and is everything in its proper places? Enter useability analysis: making sure that the layout of the page matches the expectations of the majority of your users, laying out the content in an easy-to-read format, and making sure that your site is disabled-friendly.
Having a highly-accessible website is more than just a good idea, though - for many sites, it's the law. The Americans with Disabilities Act (ADA) Section 508 states that anyone doing business with Federal organizations or in the name of federal organizations must be accessible to disabled users.