There is an article over at Practical Ecommerce titled Accessibility: How Many Disabled Web Users Are There? by Joe Dolson. It is refreshing to see more traditional sites dealing with accessibility, especially when it can so significantly affect their bottom line. As an indication that the author gets it:
I often hear business owners claim that their sites aren't used by people with disabilities, so they don't need to pay attention to web accessibility. But there's no basis for such claims because the merchant can't possibly know this information. The tracked profile of a user with a disability, via a typical analytics package, is identical to anybody else using that browser.
The author is smart enough to discard data that doesn't necessarily impact web usage — such as leg amputations, for example. While presenting the information below, the author reminds us that the Baby Boomers are getting older, and crossing the 65-year-old age barrier (see below):
The most commonly discussed disabilities affecting website accessibility are sight and hearing impairments. These specific impairments encompass 6.8 percent of the population age 15 years and older — and climb to encompass 21.3 percent of the population when you look specifically at the population over 65, according to the 2005 report. Eight-point-two percent of this same population is listed as having difficulty grasping objects — which affects the use of a mouse.
A conservative estimate says 1 out of 10 of your users could have an impairment of some sort. For every day that passes, that's another user who has aged or deteriorated in some way, making that number climb over time. That's 15.5 million potential customers. Perhaps this a better way to present the information to your ecommerce customers.
Just three days later the author posted a follow-up article on his own blog titled United States disability statistics: Measurement and sources. The author explains that while his official article still gets to the point about supporting disabled users, this post is intended to provide more detail on the numbers. The authors closing comments explain how the data is good enough for some general numbers, but lacks a little detail on specific issues:
In general, my assumption is that the data may include some individuals who struggle with reading due to dyslexia, dependent on the exact phrasing of the questions, but not all, and presumably includes no or very few individuals with color blindness.
The author (still Joe) is kind enough to provide links to the PDF versions of the U.S. Census Bureau reports he used as his data sources. Since I am also a fan of providing links to the raw data, here you go: