The pending popping of the podcast ad bubble is the topic on part six of my 10-part miniseries on the future of podcasting. (1, 2, 3, 4, & 5)Somewhere around $500 million was spent last year on podcast advertising. Not surprisingly, that number is projected to go up and up over time. But only if advertisers keep feeling good about the adsThe warm, fuzzy feelings advertisers get when they run live, host-read ads on a handful of podcasts quickly diminishes when they try to scale that to hundreds or thousands of shows. Worse, if the challenges facing influencer marketing campaigns spill over to podcasting, we’re in trouble.Yes, even if you don’t run ads on your show, a popped adverting bubble is bad for you and all of podcasting due to stifled creativity. Sure, indie podcasters will still be creative. But if big production houses find more lucrative ways to make money, they take away their big marketing dollars, which means fewer new listeners coming to podcasting, stifling growth.In the future, we will see the podcast advertising landscape change. But probably not in a way that’s better for podcast creators.Advertising is never getting completely out of podcasting. But I don't think advertising will always be the lion's share of podcast-derived revenues. As these new revenue pathways develop, perhaps they’ll be a little less-speculative in nature.Three things to leave you with:Feel free to tell me I’ve crossed the line from skepticism to cynicism. One great place to do that: Flick.group/podcastpontifications. Yes, it’s free.Check out