What is the "Reach" metric?

For the Overview and Episodes page of your dashboard, Reach is the number of unique devices that downloaded an episode of a podcast.  A single device may download more than one episode of your podcast, so the Reach number may be less than your total downloads. 

For SmartPromos, Reach is the number of unique devices that downloaded the episode containing the advertisement. For dynamic SmartPromos, Reach may be less than the total amount of Impressions if users are exposed to the advertisement multiple times.