As the Swedish dust from last week’s Spotify acquisition-palooza settles, there’s little time to wait. Slate, the veteran digital media company and purveyor of fine podcasts, announced this morning that it’s rolling out something called Supporting Cast, a new technology service meant to help podcast publishers set up paid subscription layers or membership programs.
For some Slate superfans, what Supporting Cast aims to provide should sound familiar. The service was built off Slate’s experience creating and managing Slate Plus, its long-running membership program that provides paid users with additional content. (Which, by the way, has now grown to about 50,000 members.) That extra material includes exclusive podcast episodes, which has turned out to be a potent offering — former editor-in-chief Julia Turner once told me that there is “a ton of overlap” between Slate podcast listeners and Slate Plus members — but it is something that they have traditionally…
