Before you start: make sure your podcast host is compatible with Podtrac
Podtrac Measurement works by redirecting your podcast traffic through a Podtrac server which collects and analyzes information about the download request and then sends it on to where your media file is hosted for delivery to the listener. The redirect is instantaneous and does not affect delivery of your episode file or the listening experience.
In order to use Podtrac Measurement you must either be able to edit your RSS feed directly OR host your podcast media files with a provider who provides the ability to use a third party redirect (or supports Podtrac directly) - which is true of the vast majority of modern podcast hosts with a few notable exceptions.
To see if your podcast host is compatible with Podtrac, check this list of podcast hosting companies that support Podtrac.
Alternatively, you can manually add Podtrac to your podcast feed if:
You use an in-house podcast publishing system, or
You use a podcast publishing tool that enables you to edit your feed