Hello everyone, thanks for your thoughtful comments and "comedy" ;-). A few responses:

Robin: You have an interesting idea about ad placement consolidation across multiple podcasts, but unfortunately I think the variety of podcasting tools and audio standards, the lack of quality metrics, and the manual processes involved would still present problems. That said, better tools or technologies could eliminate some of these obstacles.

No Name: Excellent point! Television, the Internet, and radio did not achieve mainstream success in the first few years of operation, yet became runaway successes later. However, I would like to note that other technologies -- most notably, the World Wide Web and the iPod -- did achieve success within a year or two of being introduced to the public. Right now, podcasting is in its fourth or fifth year, and I believe it is failing. On the other hand, podcasting or its descendant will probably succeed on a large scale, once the many hurdles outlined above are overcome, but that may take many years.