Pacing determines the speed at which your line item is delivered. It is set to As Fast as Possible by default, meaning ads are served whenever the line item meets the delivery requirements, until the goal is met. Pacing set to Evenly delivers the line item consistently over the span of its run time. A Daily Pacing option is determined by the number of impressions in the Daily Goal, and can itself be set to Evenly or As Fast as Possible.
When pacing Evenly, the system looks at the total line item goal and distributes the required impressions across the run. As delivered impressions grow, the system continually adjusts priority and pacing to stay on track. If the run has more than one flight, pacing Evenly distributes the line item across the remaining flights.
For example, a line item with a 10,000-impression goal and two five-day flights delivers roughly 1,000 impressions per day when active. If listenership drops one day and only 900 impressions are delivered, the outstanding 100 are redistributed across the remaining days as the system readjusts to meet the goal.
| Day | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | Total |
|---|---|---|---|---|---|---|---|---|---|---|---|
| # of Imps. | 1,000 | 1,000 | 1,000 | 1,000 | 1,000 | 900 | 1,025 | 1,025 | 1,025 | 1,025 | 10,000 |
Make sure you set the Daily Goal high enough that, multiplied by the number of days in the run, it can reach the total line item goal. If the Daily Goal is too small to reach the total impression or spend goal, a warning message appears.
Pacing also feeds ad selection: among line items of the same priority, one pacing behind is selected over one that is on pace. See How does ART19 choose between multiple line items? for how that fits together with Priority and CPM.
See also: How are Ads Selected for an Episode? · How does ART19 choose between multiple line items? · Line item settings reference