If you've wondered about the specifics about Wizzard's premium service, I went over to Marc Maron's podcast to see what he's offering through this service.
You can purchase his phone apps (both iPhone and Android), and you can sign up for the premium website (if you don't have a smart phone). Wizzard announced they launched a paid service this week, and this enables you to have a “Net Flix” type of setup where people pay a monthly fee to access your content. You can specify which content is free, or you can specify if its “premium” and Libsyn's system blocks that content (Libsyn is owned by Wizzard media).
When I looked at Mar'cs site he has set his pricing at $1.99 a month, or $4.99 for 6 months, or $8.99 for a year of access to premium content.
Wizzard/Libsyn has all of this built into their system, so if you are using them for your media hosting. They've made it pretty easy. What you can do is use your WordPress website to promote your free items, and use the Libsyn blog (that comes with your hosting) for your “premium” content area. I also see where people who have purchased the smart phone app for Marc Maron can put in their premium membership details and access the premium content through their phones. If you're looking for a quick and painless option, this might be it.
While you can't offer smart phone apps (unless your a developer yourself) like Wizzard, you can offer a premium site without adding a middle man (if you are using a WordPress site) by using a membership plugin called Magic Members ($97).