Here are some of the usability and data accessibility issues with Flash.
- You can’t select, copy, or paste text
- Your browser’s font override features won’t work, so you can’t adjust the font or its size
- Your browser’s built-in in-page search won’t work
- You can’t use the keyboard to scroll through the text
- You can’t parse or scrape the data in any way
- The design is fixed-width, so it’s not going to work well on different screen sizes
- Browser plugins, like Greasemonkey, can’t adjust anything to augment the content
- SEO is near non-existent
- Tracking takes more effort
So, if you are going to create a flash site, make sure you create an HTML alternative. This will please both Accessibility aficionados and your users, who contrary to some peoples views, really do like the choice. It will also provide much better SEO for your site.