What’s the Difference Between a Download and an Impression?

When using PAID to monetize your podcast with programmatic ads, it’s important to understand the difference between a download and an impression, two key metrics when measuring ad performance.

What is a Download?

A download refers to the listener accessing your podcast episode through the successful delivery of a podcast episode file to the listener’s device. This can occur through manual downloads, automatic downloads via subscriptions, or progressive downloads during streaming. Downloads are tracked using server logs, which capture valid requests for podcast files.

At RSS.com, we follow IAB guidelines, and you can learn more about downloads here.

What is an Impression?

An impression refers to an ad unit being delivered to a listener. If your episode has multiple ad slots, like 2 pre-rolls, 4 mid-rolls, and 2 post-rolls, you have 8 possible ad placements in a single episode.

That means: 1 episode download could generate up to 8 ad impressions

But here’s where it gets nuanced: impression counts depend on how much of the episode is actually streamed or downloaded, and whether the programmatic market has enough inventory.

If a listener only plays the first few minutes, only the pre-rolls might get delivered, so fewer impressions are counted. And if there isn’t enough ad inventory at the time, some or all ad slots might remain unfilled, meaning no impressions for those slots.

So, a full episode download doesn’t necessarily equal full impressions. It all depends on listener behavior and ad availability.