What’s the big deal with podcasting? Despite all the buzz, Ad Age says the Web’s newest Wild West industry lacks direction and established players. Effective third-party audience measurement is one way to settle an industry that will ultimately revolve around the buying and selling of ads, but for the time being, usage is so small and reports are so varied, marketers are forced to sit on the sidelines and wait. Varying reports say anywhere between 5 and 10 million people have downloaded podcasts; eMarketer claims regular listeners–those who download at least one podcast per week–number about 3 million per week. Meanwhile, future projections are also all over the map: Forrester thinks the number will be 12 million listeners by 2010, eMarketer says 50 million (but 15 million regulars), and Bridge Ratings thinks the audience could reach 75 million. All told, the audience is small right now, but just how small is difficult to say. The result, one MediaVest executive said, is “a Long Tail phenomenon where you have hundreds or thousands of podcasts with a couple thousand listeners. In isolation, they may not be advertising viable but when you start aggregating them together, all of a sudden it makes sense,” he said. Ad Age mentions three examples of such podcast aggregators: PodBridge, Podtrac and PodShow. But the questions remain, how many are actually listening–and who are they?