Metrics
The definitions below are the ones the dashboard reports on for TVNZ. The first table is the reference; the sections after it explain the ideas behind the numbers — how impressions are counted, what an impact adds, why 30-second equivalents exist, and how capacity, fill rate, reach and frequency relate.
Definitions
| Metric | Definition |
|---|---|
| Impressions | The number of advertising impressions delivered. Each one is an ad shown to a viewer or subscriber |
| Impacts | The total number of ad events across main profiles and co-viewers — every person exposed, not every ad served |
| Adjusted Impressions | Impressions converted to a 30-second equivalent, so ads of different lengths compare consistently: a 60-second ad counts as two, a 15-second ad as half |
| Adjusted Impacts | Impacts converted to the same 30-second equivalent |
| Capacity (Impressions) | The number of impressions that could have been delivered from the available inventory. Each impression is one unit of capacity |
| Available Capacity (Impressions) | Advertising opportunities that were available but not filled with a paid ad — filler ads and unused slots within the breaks |
| Impact Capacity | The number of impacts that could have been delivered across the ad breaks in TVNZ inventory |
| Adjusted Capacity (Impressions) | Capacity converted to a 30-second equivalent |
| Impact Adjusted Capacity | Impact capacity converted to a 30-second equivalent |
| Fill Rate (Impressions) | The share of capacity filled by delivered impressions: Impressions ÷ Capacity |
| Adjusted Fill Rate (Impressions) | The share of 30-second-equivalent capacity filled: Adjusted Impressions ÷ Adjusted Capacity |
| Impact Fill Rate | The share of impact capacity filled: Impacts ÷ Impact Capacity |
| Impact Adjusted Fill Rate | The same on a 30-second basis: Adjusted Impacts ÷ Impact Adjusted Capacity |
| Reach | The number of different people (unique subscribers) exposed to the advertising at least once |
| Digital Reach | Unique digital subscribers reached, main profiles and co-viewers included. A subscriber counts once however many impressions they received |
| Linear Reach | Not yet calculated, so shown as 0. Will be the number of unique people or households who saw a TV advertisement at least once in the period |
| Frequency | The average number of impressions per subscriber reached: Impressions ÷ Reach |
| Impressions % | An item's share of the impressions in the current selection: Item Impressions ÷ Total Impressions × 100 |
Impressions
An impression is counted as one showing of an advertisement. On digital it is counted each time GAM serves an ad; on linear TV it is estimated from Nielsen audience ratings and the broadcast schedule. Where the data comes from covers both in detail. Digital impressions are counted; linear impressions are calculated — and that is the difference to keep in mind whenever the two sit side by side in Total TV reporting.
| Linear | Digital | |
|---|---|---|
| Primary source | Nielsen ratings and the spot schedule | Google Ad Manager |
| Calculation | Audience rating × audience universe | Valid ads served |
| Audience measurement | From Nielsen's panel | From digital viewing and profile data |
| Stability | May change when consolidated ratings arrive | Does not change |
Impressions can be analysed across campaigns, channels, programmes, advertisers and every other dimension.
Impressions and impacts
Impressions count ads delivered. Impacts count people exposed: every viewer of an ad, the main profile and anyone co-viewing with them. Because more than one person can watch the same ad, impacts can exceed impressions.
- Linear: Nielsen's panel measurement already accounts for co-viewing in its ratings, so no further audience calculation is applied — impressions equal impacts, and the two metrics show the same value.
- Digital: a single impression can reach several viewers on one screen, so impacts can be greater than impressions.
30-second equivalents
Ads come in different lengths, and a 15-second spot is not the same amount of advertising as a 60-second one. The Adjusted metrics put everything on a 30-second basis: a 60-second ad counts as two 30-second equivalents, a 15-second ad as half of one. Adjusted Impressions and Adjusted Impacts do this for delivery; Adjusted Capacity does it for inventory. Use them to compare campaigns or inventory where durations vary.
Impressions %
Each row's share of the impressions in the current selection. Break impressions down by channel and Impressions % is each channel's share of the impressions in view; add a filter and the shares are recalculated over what remains.
Impressions % = (Item Impressions ÷ Total Impressions) × 100
Capacity
Capacity is the advertising space TVNZ has to sell: how much advertising could have been delivered within the available breaks. It is worked out separately for digital and linear inventory.
Digital. TVNZ fills every available break on TVNZ+ with an ad, paid or filler, so capacity can be counted from the impressions delivered within each break.
| Metric | On digital |
|---|---|
| Capacity | The maximum impressions that could be delivered, sold and unsold together. One impression is one unit |
| Impact Capacity | The maximum impacts that could be delivered. One impact is one unit |
| Available Capacity | Opportunities that showed a filler ad instead of a paid one — available inventory that was not sold |
Linear. Capacity is calculated from the advertising spots scheduled within each ad break — the group of spots shown together during a programme.
| Metric | On linear |
|---|---|
| Capacity | Delivered impressions plus the available commercial airtime |
| Impact Capacity | The same as capacity — impressions and impacts are equal on linear |
| Available Capacity | The advertising time available to sell on a channel: filler ads, unused ad minutes and potential ad opportunities |
Adjusted Capacity puts the inventory on the 30-second basis: the 30-second equivalent impressions served plus the 30-second equivalent opportunities that went unused. Impact Adjusted Capacity does the same for impact capacity.
Fill rate
Fill rate is how much of the available advertising space was actually used.
Fill Rate = Impressions ÷ Capacity
With a capacity of 1,000 impressions and 800 delivered, the fill rate is 80%. A high fill rate means most of the space was sold; a low one means more was left unused.
Because ads differ in length, Adjusted Fill Rate makes the same comparison on 30-second equivalents — Adjusted Impressions ÷ Adjusted Capacity — and gives a truer view of inventory use when durations vary: 750 thirty-second-equivalent impressions against 1,000 of capacity is 75%.
Impact Fill Rate is the audience version, Impacts ÷ Impact Capacity, and Impact Adjusted Fill Rate the same on 30-second equivalents.
Reach and frequency
Reach is the number of different people — unique subscribers — exposed to the advertising at least once. On digital it counts each unique viewer once, the main profile and each co-viewer alike, however many ads they saw. Linear reach is not yet calculated and shows as 0 until Nielsen reach data is in place; a combined cross-platform reach, with the overlap between digital and linear, is planned for Phase 3.
Frequency is the average number of impressions each reached subscriber received.
Frequency = Impressions ÷ Reach
If 1,000 subscribers were reached with 3,000 impressions between them, frequency is 3: on average each was exposed three times.
Related
- Where the TVNZ data comes from — sources, overnight versus consolidated ratings, daily processing
- Dimensions — what you can break these metrics down by