These two don’t mix well. Search engines cannot read Flash because essentially Flash is just a movie/picture, much like a jpg, or a photo. Search engines cannot read or understand pictures really. They only understand actual text. In short there are a few options for people that insist on Flash only, or Flash heavy sites.
Most search engine experts, as well as ecommerce experts say to stay away from Flash if keeping the visitor on your site is important. In fact, most experts advise strongly against it (see sources below). Exceptions for media and branding sites exist, but this is the minority out there. Avoid using Flash for Navigation elements especially.
Most of these techniques require Flash developers who know their stuff:
#1. Make an XHTML version of the site using Search Optimized Flash Architecture (SOFA). Here is a detailed white-paper on how its done (PDF) http://www.avenuea-razorfish.com/articles/SOFA.pdf Send the XML content into the noscript tag.
#2. Another technique involves using SWFObject(). or FlashObject Basically a JavaScript is used to determine whether the visitors browser supports Flash enabled or not, and if it’s not, then it displays an alternate HTML page (in a DIV). Learn more about this technique here.
#3. Adobe (the makers of Flash) offer an SDK for creating an integrated, text only version of the Flash movie. “The SDK includes an application named ‘swf2html’. Swf2html extracts text and links from a Flash .SWF file, and returns the data to stdout or as an HTML document. Swf2html is provided as a compiled application, and as a static library for linked library implementation.”
Be sure the content in your HTML version of your Flash matches what is shown in the Flash, otherwise your site may disappear on the search engines.
Sources and further reading: SMarT Marketing, Bruceclay, Search Engine Watch
