Spiders Can’t Appreciate Art
We have all seen amazing sites using Flash throughout. As humans, we can appreciate these sites for what they are, and often find the compelling and professional. But the simple fact is that a search engine spider cannot read the content of a flash website.
Before you put a flash site up, look at the HTML code of the page you are presenting, and remember that is all the spider will see. Once you do that, there is really nothing left to be said on this subject, except that you may consider two versions of your site: One with flash, and one without.