Reach & Frequency
Part of Media forecasting and scenario planning
Reviewing whether extra spend would add new reach
Compare like-for-like reach forecasts at two spend levels, calculate the estimated marginal gain, and check frequency and model limits.
Compare the current plan’s forecast unique reach with a second forecast that changes proposed spend and keeps other relevant settings the same. The difference is estimated added reach under that planning method. Check frequency and eligible inventory before deciding whether the extra cost is worthwhile.
Make the plans comparable
Use the same eligible audience, Australian locations, dates, formats, creative and placement rules. State the reach unit and threshold: people estimated to receive at least one ad during the campaign differ from devices, households or people meeting a 2+ exposure threshold. Save both forecasts with their settings and dates.
Calculate the marginal comparison
In a hypothetical like-for-like forecast, suppose an A$10,000 plan estimates 80,000 people at 1+ reach and an A$15,000 plan estimates 100,000 under the same method and period.
The extra A$5,000 corresponds to 20,000 estimated additional people, or A$0.25 per estimated additional person. These invented values do not report an Australian campaign or promise that 20,000 more people will be served.
The first plan averages A$0.125 per estimated reached person. The marginal amount is dearer in this example. Whether it is worthwhile depends on who the additional people are, the campaign’s task and other uses of the budget. Added exposure is not incremental sales caused by media.
Check / Why it matters
- Extra 1+ reach
- Estimates new people under matching settings and one method.
- Change in 2+ reach and higher frequency
- Shows how added delivery may reinforce existing exposure.
- Inventory and geography
- Tests whether the added opportunity fits the brief.
- Added media and required work
- Shows the full amount the decision would commit.
- Forecast coverage
- Identifies placements outside the model.
Key Checks Before Approving Extra Spend
- Extra 1+ reach estimated under matching settings and methodRequired
- Change in 2+ reach and higher frequency evaluatedRequired
- Eligible inventory and geography confirmedRequired
- Full media and required work commitment assessedRequired
- Forecast coverage checked for placements outside modelRequired
Check the estimate’s limits
Reach is modelled. Separate suppliers may count overlapping people, so their individual gains do not establish combined new reach without a credible overlap method.
If extra spend changes dates, audience or format, treat the proposal as an alternative plan and explain those changes. If new reach is small but useful repetition grows, judge it against a stated frequency objective.
If neither is useful, retain the budget or assess another eligible placement. After launch, compare planned and delivered settings, available reach, frequency and spend. Record missing reach data as a reporting gap, not zero reach.
Reach Forecast Model Limits & Best Practices
- Reach is modelled, not directly measured
- True
- Overlapping audiences may vary by supplier
- Requires credible overlap method
- Small added reach with repetition growth?
- Assess against frequency objective
- Post-launch: compare planned vs delivered
- Record missing reach as reporting gap
