Podcasting isn't a flop. There are more subscribed-to podcasts now than ever.
The "problem" is that there are so many that rely solely on high ratings on iTunes for exposure that many never get noticed.
I've got subscriptions to about 10-12 podcasts and listen to them when I can.
I wrote AUDIO podcasting. More specifically I should have stated spoken audio. Music podcasting is okay. But the spoken podcasts are a big flop.