Hey Paul,
Dobn't know if you've heard of
http://www.patreon.com/
As you are a pretty strong content creator, be it youtube vids, articles, or podcasts I think you may be very interested in this format.
It allows those who support you and value your work to offer donations. Think of it like an ongoing kickstarter. Patrons sign up and offer a donation at a rate that they choose at a frequency that is based upon your content creation.
So for example, for every Video, Article, Podcast you release you'd be paid by your patrons. This doesn't necessarily create a paywall for your content it just lets people donate directly to you and help support the work you do.
Imagine if your dailyish email subscribers where patrons at Patreon. It would offer a way to let people get discounts on workshops and DVDs and things based upon their donation level. You could also make higher donation levels that let people talk directly to you or whatever else you can imagine as a valuable offer in exchange for their bigger donations. Early access to videos and other content, extended interview podcasts, special patron only questionnaire podcasts etc etc.
Thought it would be worth looking into.
Cheers,
Elia