win friends (and influence people)
A site built with accessibility in mind provides a better user experience for everyone. A better user experience makes for happy users and encourages repeat business. Happy users recommend sites to their friends.
Be remarkable
Marketing guru Seth Godin wrote a book called "Purple Cow: Transform your Business by Being Remarkable". In it, he talks about a group of people he calls "sneezers". Sneezers are people who become so passionate about a product that they infect others with their enthusiasm.
An accessible website can be a Purple Cow, transforming your users into passionate advocates for your services, saving you money on marketing and promotion.
Read more about Purple Cows at Fast Company: In Praise of the Purple Cow.
Influence decisions
A committed user base will influence other users, and a demonstrable commitment to accessibility could make the difference between winning a contract (particularly with Government agencies) and losing out to a competitor.
Winning friends (and influencing people) isn't the only benefit. Accessibility can make you look good too.

