Excerpt from: Podcasting at Work: 25 Questions to Ask Before Starting

We recommend producing a simple teaser or trailer for your podcast. Podcast directories provide a place to include a trailer, and some potential listeners check them out before deciding if they want to listen or follow your show. 

We also use the trailer to set up distribution for your show before releasing the first episode. Podcast directories like Apple Podcasts and Spotify require a piece of audio before they’ll accept your show, but the setup process can take a week or two. So we submit the teaser to get all your distribution channels set up in advance of your official launch date. This also allows you to start building listener interest and allows them to follow the show before episode 1 drops. And when that big day arrives, your audience can find the show everywhere they might look for podcasts. 

The teaser/trailer can be quite simple too. Many shows essentially use their podcast intro with a sentence or two tacked on. Learn more about scripting these elements.