As the producer of an established music program, I have largely been excluded from podcasting by current licensing restrictions on music downloads. (There are music podcasts, but they are either technically illegal or limited to so-called 'pod-safe' music — a small minority of the overall music catalog.)

Your piece does shine some retrospective light on the gap between the hype and hyperbole and that often accompanies new technical developments and the reality of the marketplace a few years later. I was an early critic of podcasting hype, but I think you've undervalued two of the most important characteristics of the podcast stage of the digital media revolution.

First, podcasting really has helped to democratize media by eliminating the program inventory and bandwidth limitations of conventional broadcasting. This allows not only amateurs but disenfranchised professionals to distribute their programs, and allows service to previously unserved niches. Your points about audience size and business models are less important than the fact of service to and from new constituencies — inarguably, a social good. Thus it makes more sense to evaluate many of these programs from a public service perspective, like public broadcasting.

Sustainable business models are the deeper issue, but there are other benefits to producers that tend to balance the cost/benefit equation. In practice these include intangible, reputational, creative, and indirect financial benefits to the producers, as text blogs demonstrate today. These services have to evolve their own appropriate business models. New kinds of online aggregators like the social networks may eventually provide the business platforms producers need to make their efforts sustainable.

Second, the quality standards and practices of professional mass media do not necessarily apply to small audience niche programming. A more professional sounding and better produced program like Leo Laporte's TWiT may achieve a higher audience share, along with whatever benefits that delivers to the producer, but there are already podcasts that achieve their objectives with limited quality and audiences of less than a thousand. These have to be counted as different criteria of "success."

So podcasting may never succeed in the terms you are using to measure it. Simply put, mass usage paradigms like advertising do not translate into viable business models for niche media. We are still in the early days of the digital media revolution. The beneficiaries of these new distribution technologies, whether streaming or podcasting, licensed or unlicensed, free or paid, are still attempting to find their place in the new media ecology.

Finally, along with many others I believe that podcasting, i.e. distribution of audio media media via RSS subscription downloads, will be largely replaced as a service model by streaming as wireless internet connectivity evolves. In a truly "always on" world, only a link to a given bit of content is needed and it can be delivered to the user on-demand in real time. This is the way some email systems work now; only message headers are delivered to the mail client and the body of the message is pulled from the mail server at viewing time. Another benefit of just-in-time delivery is that the user does not have the responsibility of managing bulky media files on their computer or portable device, which will be an issue for some time to come.