Let's jump into the Pro's of using YouTube Videos:
» Video hosting can become expensive; YouTube eliminates this as hosting your videos with them is absolutely free of charge.
» Your videos on YouTube come with their own MetaTags and therefore are added to any search results triggered by the ones on your website. In short; two relevant search results instead of one, both going to the same company - Yours!
» You have access to the YouTube community. This means if your video is making some noise on YouTube it might lead to direct traffic to your website.
» YouTube can be a powerful tool to brand your company, and can be accelerated by using Google Adwords to show your video to people already interested in your product using their browsing history.
Four to one.
Those are the odds stacked against you, should you choose to rather utilize Flash above YouTube.
But like anything it is a matter of perception as well as needs.
If you want something that 'pops' and gives that 'wow' effect, then Flash Videos is definitely for you, but should you wish to utilize something that is not only practical, but also adept at supporting your Online Marketing Strategy, then there is no better option than YouTube.
Not only does it cater for users of any demographic, but it also functions as an integral part of SEO, helping your website get to the front page of search engines such as Google, Bing etc.