It's just so easy. It's probably harder to not do it.
Gone are the days when a publisher could take out an ad, count on a few reviews, and have an author do a couple...
There are so many podcasts to be a guest on! How do you choose which ones are a good fit? Introducing Listen Notes. https://youtu.be/DFHEJDMktUk
If you have a podcast, you have some, well, power, authority, credibility. Just like if you have a book, you instantly have some leverage...