Olmstead v. L.C. was a case before the United States Supreme Court in 1999. The two plaintiffs L.C. and E.W. were institutionalized in Georgia for diagnosed mental retardation and schizophrenia. Clinical assessments by the state determined that the plaintiffs could be appropriately treated in a community setting rather than the state institution. The plaintiffs sued the state of Georgia and the institution for being inappropriately treated and housed in the institutional setting rather than being treated in one of the state's community based treatment facilities.
Enough Time: Users have sufficient time to read and use the website’s content. If part of the website has a time limit, users are able to turn off the time limit, or they can adjust or extend it to at least ten times the default limit (unless the time limit is essential to the website’s functionality, such as auction websites like eBay). Content that moves, blinks, or automatically updates can be paused or stopped unless it’s essential to the website’s functionality.
While legal considerations might be your biggest worry, making your site more accessible is simply good customer service. More than 39 million Americans are blind and another 246 million have "low vision," Another one million are deaf in the U.S. Add to that people with mobility issues that prevent them from using their hands and that's a huge portion of the country's buying power.
“The idea of equal access, equal opportunity has sort of evolved in its application from brick and mortar to eCommerce. At first, many companies were worried about the desktop experience. Now, the concern extends to both smart phones and devices. Wherever a consumer accesses your content – whether it be directly through the web or an app – you need to be concerned about accessibility.”
This is the reason why I think web design firms have to position themselves as solution providers and not just web guys/gals. A client doesn't need a website, they need sales. The website is just part of that solution but it's not the solution and unlike web design, service like email marketing automation, SEO, and PPC requires an experienced professional.