See, if you build your whole site in Flash it may look like you want, but it doesn't work like anyone else wants. If they can't link to the bit they like, they'll just bung your video on YouTube so they can. Which means that everyone sees a crappy-quality version, and they don't find your site. Durr.
Example: the 'Spin' video is quite, quite beautiful. If you can't be bothered clicking around on that site, however, here's the YouTube posting.
Oh the joys of flash… NOT!
Go to the Airfix site and try and find the competitions page WITHOUT flash loaded. A year’s supply of Guinness to the victor ;)