Estimating podcast reach overlap: Use deduplicated audience data to avoid double-counting recipients; Combine show reaches using A + B − overlap for accurate totals; Request network-wide deduplicated estimates for multi-show plans
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Measurement

Part of Podcast ad frequency and reach

Estimating overlap across podcasts in a network

Estimate combined podcast reach with comparable audience figures, deduplication and clear limits on cross-show overlap data.

Measurement Desk · · 2 min read

To estimate a network plan's combined reach, identify recipients counted for more than one podcast during the same period. Adding show audience figures without accounting for overlap overstates their combined total. First establish whether the figures describe show audiences or people estimated to receive the proposed ads.

Get comparable inputs

For each show, request the eligible Australian audience, dates, included episodes and counting method. A show's audience is not automatically the reach of a placement in that show. Ask whether one measurement provider can estimate recipients across all proposed placements on a consistent basis.

For open podcast downloads, ask providers to explain how they estimate and deduplicate consumers. The method may not identify people consistently across downloads. Report the method and time frame with the result.

Calculate only what the data allows

For two comparable sets, combined estimated uniques equal A plus B minus the estimated overlap. If A is 20,000, B is 15,000 and the estimated overlap is 5,000, the combined estimate is 30,000. These figures are illustrative. Their usefulness depends on a consistent matching method and reporting period.

For several shows, ask for a deduplicated network total. Pairwise overlaps alone cannot give the exact combined total when recipients may appear in three or more shows.

If only separate show figures are available, their sum is an upper bound and the largest show figure a lower bound for the combined reported sets, provided those figures use the same eligible population, period and identity method. They are not bounds on the number of actual people who heard the ads. Figures produced by incompatible methods should not be combined this way.

Steps to Estimate Combined Reach Across Podcasts

  1. Confirm consistent measurement method across all showsEnsure all providers use the same identity and deduplication approach, such as IAB PTM standards.
  2. Verify reporting period and eligible population matchAll figures must cover the same time frame and target audience (e.g., Australia only).
  3. For multiple shows, request a deduplicated network totalPairwise overlaps are insufficient for three or more shows; use provider-level aggregation.

Use overlap to assess the plan

Ask how much incremental eligible reach each proposed placement or show is expected to add. A large show may add little to an existing plan if many estimated recipients overlap. A show with less overlap may still be a poor fit for the campaign's Australian audience.

Keep forecasts separate from delivered results. At campaign close, request a deduplicated estimate for actual ad delivery over the full reporting period. If the provider cannot match recipients across every publisher or platform, identify the covered inventory and report the rest separately. Do not present a partial network estimate as a count of people who heard the message.

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