The easiest way to market your show is to join relevant groups in your niche and share your episode on the day of your presentation.
First, make a list of groups you've joined and split them into buckets of pro-self promotion and anti-self promotional groups.
How to Share Your Show Depending on the Type of Group
Then engage a little each week with the anti-self-promotional groups before posting a link to your show. This will ensure you have a greater chance of your episode's post being approved by the admins and help avoid you from being banned by the group.
Remember, every group is run independently and can have arbitrary rules. Don't take it personally if someone bans you. Just move on and find more relevant groups to join.