We build all different types of websites from XHTML to Flash and always advise against creating a Flash intro for websites. There are many disadvantages to Flash intros:
· They increase the file size of the homepage. This is one of the most important disadvantages of using Flash intros on your website: it increases the time the homepage takes to load. Expecting your visitor to first wait while the Flash intro loads and then expecting them to read your message is unreasonable. It would be like a telemarketer expecting you stay on the line through 30 seconds of music before they even start their pitch.
· They are outdated and look cheesy. This in not circa 2001; just cause we can do it, doesn't mean we should.
· If you add music and sound files, that's a huge no-no! This is intrusive on your visitor who may not want to listen to your sound file and could steer them away from your site.
· The most important disadvantage of using a Flash intro is that most search engines have difficulty indexing Flash, and thus it will not help you in the SEO department.
The conclusion is that most Flash intros serve little purpose and actually hurt websites. Remember that visitors come to your site to find information, very rarely entertainment derived from Flash intros (unless you have a website about entertaining Flash intros).