Every serious podcast number you will ever see — your host's dashboard, a sponsor's invoice, a promotion service's report — is supposed to be measured the same way. Here is what that measurement actually requires, and what it deliberately throws away.
IAB v2.1 is a measurement standard published by the IAB Tech Lab, the technical arm of the Interactive Advertising Bureau. It exists so that "download" means the same thing at every podcast host, and so a sponsor paying for 50,000 downloads is buying something defined rather than something claimed.
A request for your episode audio only becomes a download when it passes three separate tests. Fail any one and it is discarded — not flagged, not discounted, discarded.
The listener's device has to receive enough of the audio file to play at least one minute of content. Not one minute of listening — one minute of bytes delivered.
This single rule kills the most common form of inflation. A page that pings a URL, a preview that grabs the first few kilobytes to read the ID3 tag, a link checker touching the file — all of them make a request, and none of them transfer a minute of audio. They do not count.
The IAB Tech Lab maintains a list of known spiders and bots, and a compliant measurement system filters every request matching it. Beyond the published list, hosts add their own detection for crawlers, previewers, and automated agents that fetch media.
This matters more than it sounds. A meaningful share of raw requests to any public audio URL are automated. A system that counts raw requests and calls them downloads is not measuring an audience; it is measuring the internet.
The same listener requesting the same episode inside a 24-hour window counts once. If your phone loses signal mid-episode and re-requests the file four times, that is one download.
Deduplication is why your download count is always lower than your server's request log, and why it should be. A vendor whose number is higher than your host's is almost certainly counting the requests your host correctly threw away.
The standard gives you a test that takes about a minute and settles most arguments: open your own hosting platform and compare.
Megaphone, Art19, Libsyn, Buzzsprout, Podbean, Simplecast, Captivate, Acast and the other major hosts all measure to this standard. Their number is the one your sponsors will audit and the one the industry treats as real. If a promotion service reports downloads your host never recorded, the honest description is that they did not happen.
This cuts both ways, and it is worth saying: a service reporting fewer downloads than your host is under-reporting, which is its own kind of broken. The two numbers should converge. When they do, the measurement is working.
The IAB Tech Lab runs a certification program that audits a measurement provider's implementation against the v2.1 guidelines. A certified host has had its filtering, byte thresholds, and deduplication independently reviewed. Most major podcast hosts are certified, and sponsors increasingly require it before accepting a download number as the basis for payment.
Because it is supposed to be. Deduplication removes repeat requests from the same listener within 24 hours, bot filtering removes automated traffic, and the byte threshold removes requests that never transferred a minute of audio. The gap between raw requests and IAB downloads is the measurement doing its job.
No, and conflating them is the most common mistake in podcast analytics. A download means the audio was delivered to a device. Whether a human then listened, and for how long, is a separate measurement your host may or may not report. Downloads are what sponsors buy because they are what can be measured consistently; listening depth is what tells you whether the show is any good.
No. The standard measures delivery of audio bytes, not playback. A podcast app that auto-downloads new episodes overnight generates real IAB downloads for episodes nobody has opened yet — which is exactly how subscription-based podcast listening has always worked, and why the standard is written around delivery rather than playback.
Podbooster runs targeted ads that bring real listeners to a specific episode, and counts a download only when it meets the IAB v2.1 standard — so the number matches what your host shows. $0.80 per verified download, from $100, no contract. Most campaigns finish in two to five days.
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