He does this as an example of how podcast listeners aren't just listeners. Rather they're participants in the conversation. The whole discussion started with an observation by Jason that even though podcasts don't have links, people link them anyway. This got labeled "meme extension."
You might view this as a generalization of links to something more abstract. Or you might just view meme extension as something that's always gone on and links were just a cheap proxy for it in the hypertext world.
I think I'd lean toward the former because it's really the acceleration and expansion of conversation that's made this viable (another theme in Part II of Hangup Gang). I've struggled in the past to understand what Steve Gillmor means when he talks about gestures and "links are dead" but I'm starting to understand it better with this example.