Can I make podcasts about content I’ve already posted? Does that help?

Yes, and it’s an easy way to get more mileage out of work you’ve already done. Turning a blog post, case study, or webinar into a podcast episode gives that content a second life in a new format, on new platforms, with its own SEO and backlink value. It also works in reverse: a podcast conversation can become the source material for a future blog post, so the repurposing runs both directions.