1. Increase Market Share and Audience Reach Improve usability for non-disabled and disabled visitors; Support for Low Literacy Levels; Improve Search Engine listings and Resource Discovery; Support for Semantic Web; Re-purpose content for multiple formats or devices; Increase support for Internationalization; Assisting access for low-bandwidth users.

2. Improve Efficiency Reduce site maintenance; Site Search Engine Improvements; Re-purposing Content; Address server-load; Address server-bandwidth.

3. Demonstrate Social Responsibility

4. Reduce Legal Liability

Here you can read whole draft: http://www.w3.org/WAI/bcase/benefits.html

Accessibility is critical for a web site's success

This narrow focus is at expense of a much larger segment of society with milder impairments, such as partial sight, poor hearing, and poor language skills. The needs of this larger group can be more easily accommodated with simple and inexpensive design tips such as resizable text, large tactile buttons, and clear, easy-to-follow instructions.

We should try to look at things from point of view of people who have disabilities. For example, in UK alone, there are 8.5 million people who are classified as having some sort of disability. That's a big percentage to exclude from web; from a moral viewpoint, it is surely wrong, but from a commercial viewpoint, it is disastrous.

When designing web pages, try putting them through a text reader, like ones used by those with visual impairment. You will soon realize how difficult it can be for a user who cannot see that a new window has opened - hence need to overtly tell users that a new window has indeed opened.

Apart from moral and commercial considerations, there is also legal. The United Kingdom enforces Disability Discrimination, which requires all web sites to show that they have taken steps to enable access.

With a little bit of thought, accessibility is relatively easy to implement. It does not require you to do away with JavaScript, Flash or other Multimedia features, just as long as you provide an alternative, so your visitors have a choice.

Epilogue

"For people without disabilities, technology makes things convenient," says Judith Heumann, U.S. Department of Education's Assistant Secretary of Office of Special Education and Rehabilitative Services, "For people with disabilities, it makes things possible." Just keep that in mind.-