Hosting a podcast should never be a one-way dialog.
The main disadvantage you have as a host is that your show isn’t live and “in the moment.” All the more reason to keep your audience engaged. Here are some quick ideas to consider:
*Set up a voicemail for listeners to call (you can use Skype or Google Voice for that). Encourage listener participation (“Is XYZ really the way to go? Call ____”), and air the best calls on your next show.
*Social media. If your show doesn’t have a specific social media presence (Facebook, Twitter), your individual profiles should be publicly accessible and used to interact.
*Email. Create a dedicated podcast email address (which will also be useful as you create social media accounts for your show). Encourage email feedback in each episode. Build a database from those emails to market to later.