A lot of the examples in this article are kind of gimmicky. MailChimp, for example. You would be better off ignoring the chimp, who usually links to YouTube time-wasters as if they were important messages (the chimp is usually the "visually loudest" item on the page). Personality? Yes. But maybe not a good inspiration for your own product's personality. Maybe too much trading-off of utility. To me, the web product th…
http://blog.mailchimp.com/one-meeeellion-users/
Also, they do give you the "non-cheeky" option, so there's that.
Completely agree re: Feedburner. :)