New media, such as Flash4, makes this possible. You could add a dHTML ticker or a Flash4 animation, but you could also make an entire site with it. Visitors will not wait 20 seconds before they can finally see the page. If there is one thing you really have to pay attention to is your spelling. If you don't check it and there are mistakes, visitors will get confused and the chance is big that they won't understand it and leave.
Broken links are very confusing.
It will make visitors leave because if they click on a link, they are interested. If they don't get what they wanted, they will immediately leave the site and browse to another site. Add a mailing list to your site. Get a short url or a domain. At cjb.net you can get a free redirection url with email and some more features.