While this may work in the movies, it doesn't work in podcasting. You need to promote your show (and I mean beyond getting it listed in the directories).
Some people say there is a "Discovery problem" in podcasting, but if podcasting has an issue so do music, books, and magazines.....
It would help if you found a way to let your target audience know that you exist, and I play a clip from Gary Arndt from the Everything Everywhere podcast, who is spending money to get his show in front of people to help grow his show.
Start Your Podcast at
My Full Interview With Gary
Everything Everywhere Podcast