Counting downloads

Downloads are counted to the IAB Podcast Measurement Technical Guidelines v2.3. In practice that means two rules do most of the work: repeated requests from the same listener for the same episode within a 24-hour window count once, and requests that never transfer enough of the file do not count at all.

From requests to verified downloads

Every figure on a report comes from one chain, and the chain is printed on every report so any number can be traced back through it:

  Requests received                     every request that reached the prefix
– removed as duplicate or non-qualifying IAB deduplication and file-threshold rules
= Downloads (IAB-counted)
– declared bots                          traffic that identifies itself as automated
= Measured
– invalid traffic                        requests showing signs of manipulation
= Verified

Each line is a subtraction from the line above it. Nothing is added back, and no figure is adjusted to make the chain balance — if it does not reconcile, the report says so rather than correcting itself.

The two kinds of excluded traffic

General invalid traffic (GIVT) is automated traffic that identifies itself: known bots, crawlers, and datacenter infrastructure. It is routine, present in every feed, and never charged to an advertiser.

Sophisticated invalid traffic (SIVT) is traffic that does not declare itself but behaves in ways real listening does not. This is what an audit report prices, because it is what an advertiser paid for and did not receive.

Both are industry-standard terms (IAB, MRC). They are reported separately because they mean different things: GIVT is noise to be removed, SIVT is a finding.

What is not published

The individual signals behind a SIVT classification, and how they are weighted, are not published. Anyone trying to make automated traffic look like listening would read that list as a checklist.

What is published is the framework above, the definitions below, and the full chain on every report — enough to check the arithmetic and to question any figure, without handing over the means to evade the measurement.

Terms used on reports

Rates are always calculated from the pooled totals of the population being described, never by averaging the rates of its parts.