Don't assume that your Podcast competition is doing what they're doing because they have a specific strategy. Also, never assume that if they do have a strategy, that the strategy is solid. Many things are done online in Podcasting because someone got some bad advice somewhere. Then someone copies it, as does another, and then it gets taught in some $7 ebook. If it seems to good to be true - it just might be. If you can't make the numbers add up, it might be because the numbers simply don't add up.