I’d just tell him that flash content is hidden from google. If he wants people to be able to actually find, and read his articles/content/advertisers ads, then flash is definitely a no go.
1. Show him the google webmasters page, specifically:
http://www.google.com/support/webmasters/bin/answer.py?hl=en&answer=35769
Go to ’technical guidelines’ section, 1st point, with him:
- "Use a text browser such as Lynx to examine your site, because most search engine spiders see your site much as Lynx would. If fancy features such as JavaScript, cookies, session IDs, frames, DHTML, or Flash keep you from seeing all of your site in a text browser, then search engine spiders may have trouble crawling your site."
2. Then fire up a lynx browser, and go look at some flash sites with him watching. Nothing will show up for any flash content you look at.
3. If he’s any kind of a business person at all, that will be the end of flash forever.
Dave
(Ive been forced to do this 3-4 times before, when biz clients want non-html designs done for the web. Worked every time.

)