When I first came up with the concept for Yahoo! Games back in 1997, the guiding principle of the product was that it required the user to install no software. Lack of friction in user adoption drove everything about the product, from the selection of classicgames.com to the games we chose to implement. It was this lack of friction that allowed us to go from launch to number one gaming site (where it's been ever since) in less than four months.
There is a very real danger that friction will kill podcasting. There's no question that it is greatly slowing growth. Where is the friction? RSS subscription is not as straightforward to the naive (mainstream) user as it should be. Sharing and forwarding podcasts is a big hassle (there goes viral growth). The iPod is only a connected device via a wire. Getting feedback to the author is a hassle. Keeping a portable device filled with timely content is a hassle. Notifying a listener of new content requires work on the listener's part. It's even worse on the phone -- add software handset installs and data plans into the mix, and growth is totally mired.
At Foneshow we've worked hard to eliminate these friction points. I think we've succeeded.