Once you've imported your podcast to Omny Studio, you can easily migrate to Omny Studio without losing your existing subscribers. All you need to do is tell Apple Podcasts and the other podcast directories and apps to pull from your new RSS feeds. This is done by applying a re-direct from your old feed to your new feed.
Migrating from Megaphone
You'll need to contact Megaphone support using their live chat window to set up a redirect.
Here's a template with all of the information they'll need.
I'm moving my podcast to a new host provider and kindly request that you apply a redirect for the following show ASAP
Can you please apply a 301 permanent redirect from[INSERT Megaphone RSS]to[INSERT NEW OMNY STUDIO RSS]
We will need this redirect kept in place for a minimum of 4 weeks.
Please let me know if you need any more information and an advised timeline would be greatly appreciated as well.
Thanks in advance.
You can find your Omny RSS feed using this guide: http://help.omnystudio.com/frequently-asked-questions/where-is-my-rss-feed