Great article Newt. I can testify to the long term effectiveness of an email newsletter–especially when the content also lives on your website. Expert content has all the benefit you mention as well as being valuable contributors to search traffic, client resources, and demonstration of expertise.
I’d also add that for B2B companies they should resist the urge to buy a list and instead build a true opt-in subscriber list slowly over time based on the value of the content.
Thanks!