In 2002, Malcolm Gladwell wrote a book called (NOT an affiliate link). Obviously, the book came out long before podcasts, but Gladwell attempts to shed light on the factors that must come together for something to start the meteoric rise to fame and fortune.
Brookers was the first You Tube star. A teenage girl who broadcast about her life daily-ish and was picked up by Carson Daly productions. Nobody quite knows what the attraction was, but her audience was large enough to attract main stream media.
Someone thought that was a great idea and tried it again with Lonelygirl15.Sadly, it didn't take that long for Lonelygirl to be exposed as a manufactured person. Manufactured by a group of filmakers in an attempt to...what. We're not really sure.
I've written before about why viral marketing can't be manfactured. In general, people are more likely to feel ripped off when the fake is uncovered and any possible love thus far generated for the product or service is not only lost, but replaced with bad, bad feelings.
I wish I had some advice about how to create viral marketing, but I don't. Oh wait, yes I do: if you can't make it - don't fake it.