Podcasts are almost like listening to 30 minute to an hour segments of an audiobook, except narrated with unscripted speakers; usually. You'd be surprised how much of what you might think of as an ordinary podcast done by an individual or a couple aren't scripted but they are. The average solo shop Youtube content creator will say that it takes roughly 20 hours of video and sound editing time for every one hour of finished content. Ads pays podcasters roughly $10/thousand listens for short ads, up to $25/thousand listens for longer ads. Let's say that you're Ira Glass of This American Life with 2 million listens per weekly episode.
2 million / 1000 = 2000 x ($10 or $25) = $20,000 to $50,000 potential ad revenue per episode
Influencer Marketing website has an interesting calculator of how profitable podcasts are. This year (2023), podcasts will exceed $2 billion in ad revenue.
But after deducting all the production costs, it still makes more sense for Podcasts to feature many ads. New podcasts are likely to have no ads or start with a couple really short ads at the beginning of the podcast. More established podcasts seem to have ads at the beginning, middle, and end of the podcast. But, how many ads should you serve up to listeners and is it more about greed than content? If you serve up so many ads that you lose listeners. Even though the Apple podcast app has a feature that lets you skip ahead (or "rewind" a few seconds), some podcasts have 4-6 minutes of ads.
When you think of the spoken word, it's roughly 1 page of scripted content per minute or 500 words per page. If you have unique and original podcast content that's 10 minutes long (of just content, no ads), that's 10 pages of words that a human needs to write for the podcast. There is just something about human-written content that is more impactful, meaningful, or entertaining.