Become a Guest on a Podcast
One way to get in front of a large number of people in your niche is to be a guest on a podcast. The time you invest into being a guest is minimal—usually just a few hours, including preparation, recording, and promotion. Yet it potentially gets you in front of hundreds or thousands of people in your niche.
To become a guest on a podcast, you can reach out directly to the host of shows you are already aware of and pitch them on the value you would bring to the show and its audience. You can also use podcast-matching services like PodMatch.com or PodcastGuests.com to find opportunities.