Many website owners want to build their business website using Flash to WOW their visitors. The problem is that flash content doesn’t get indexed by the search engines and therefore your site will not gain high rankings. Search engines only index textual content, not images, video or javascript. It may be possible to get your flash site ranked if you have lots of high quality links pointing to your flash web page however it will take a great amount of effort. Also there is no guarantee it will work because you’ll be competing with non-flash sites.
Why You Shouldn’t Use Flash