Before you even begin designing your website, you should consider how you will use it to your advantage upon completion. Some owners make an event out of the launch of their website to create some buzz about their brand. Others line up their best customers to give testimonials on their new site via copy or video content so they, and these customers, have something to say and share on social media.
The Federal Communications Commission (FCC) enforces regulations covering telecommunication services. Title IV of the ADA covers telephone and television access for people with hearing and speech disabilities. It requires telephone and Internet companies to provide a nationwide system of telecommunications relay services that allow people with hearing and speech disabilities to communicate over the telephone.
The gray area is a matter of scale and purpose. If you have a small business which serves as specific market it's a good idea to make the site as user and disability friendly as possible. If, however, your market serves segments with a likeliness to have various handicaps or disabilities you should address that with an ADA Compliance review of the site. Also consider the scale and purpose of an organization. Publicly traded large businesses need to concern themselves more than a single location family owned retailer and if someone sues your flower shop because the text was too small or didn't have "image alt tags" causing them distress... That's pretty frivolous and would likely not stand.
The ADA is the Americans with Disabilities Act, passed almost 30 years ago in 1990. This act was originally put in motion pertaining solely to physical location. It requires establishments to provide people with disabilities easy access to various levels throughout the business. This act was set to achieve an equal experience to all people, handicapped or not.