Pulse Distribution Engine

Delivery pacing

The Pulse Distribution Engine uses a delivery algorithm which takes numerous pieces of data into account (for example, goal type, targeting and prioritisation, site traffic, insertion policy settings, ad weights, and clash protection) when deciding which goal to pick and which ad to display.
Note: For more detailed documentation around Pulse Ad Decisioning, please contact your Account Manager.
The main goals of the Pulse Distribution Engine are to:
  • make sure all goals reach their configured delivery goal,
  • distribute the delivery evenly across campaigns and time,
  • avoid under- and over-delivery,
  • distribute ads from different goals according to the Pulse distribution and prioritization rules,
  • maximise your revenues and deliver on your advertiser commitments.
Pulse's strength lies in its strategy to deliver campaigns dynamically over the campaign period by using real-time data which is recalculated in every ad call. As a result, Pulse:
  • accounts for changes in traffic patterns and delivers a bit more on days with high traffic and a bit less on days with low traffic,
  • maximises fill rates and ensures that inventory is not wasted by trying to follow a strict daily cap,
  • ensures campaigns deliver a bit less on days where other campaigns need more impressions, and then increase again a few days later to catch up.
Note: There are also a number of settings in Pulse which you can manually adjust to optimise your campaigns. For more information, see Campaign Optimisation.

Ideal delivery

All impression goals (including quartiles and click-throughs) with an end date in Pulse should deliver according to an ideal delivery curve to ensure an even distribution during the entire goal period and at the same time safeguard against over- and under-delivery. The delivery algorithm has a built in pause and brake mechanism which prevents the goals from over-delivering and finishing too early, leaving you without ads to display until the end of the goal's lifetime. The ideal delivery curve has a built in safety margin which prevents under-delivery at the end of a goal's lifetime and goals strive to be as close to this ideal delivery curve as possible.

Pulse ideal delivery

Dealing with under- and over-delivery

Possible reasons for under-delivery:

  • Less traffic than expected.
  • Uneven site traffic.

    Example: You have a goal that is a week long and needs to deliver 1000 impressions. From historical data we know you get most of your traffic on Thursdays because of a popular show. After 3 days, you are 3/7 into your goal time-wise, and 10% into the expected traffic. This is because Pulse expects the Thursday spike so it delivers fewer ads the first 3 days and saves the impressions for Thursday. For the first 3 days the goal might seem like it is under-delivering, but after the traffic spike on Thursday the delivery should be on track. If the delivery is not on track after Thursday, then Pulse tries to catch up.

  • Too specific targeting that limits the ad to a very small number of potential viewers.
  • Global targeting rules are different from the campaign/goal targeting rules and you did not override them.
  • You are overbooked by selling 1 million impressions for a day, but only have 500 000 views in a day, which means the higher prioritized campaigns/goals deliver before the lower prioritized campaigns/goals.
  • You changed campaign priority but forgot to change the goal priority so they match, or you do not have the “inherit campaign priority settings” option on.

Possible reasons for over-delivery:

  • Configuring goals with a short lifetime and a low delivery goal compared to available inventory.
  • Issues with third-party ads causing passbacks to be used.
Note: A common cause for concern is related to subsequent changes made to goal configuration during its lifetime, for example shortening or extending the goal's lifetime and/or increasing or decreasing the delivery goal, which can make it seem like the goal is under- or over-delivering. However, this is not an issue with the delivery, just a reaction to the change you made until the delivery pace adjusts to the new configuration.

How Pulse prevents under- and over-delivery

  1. The image below shows a goal under-delivering and trying to catch up.

    Under-delivering goal catching up

    Catching up: when the goal is under the linear delivery, in this case the black "midroll linear aggregation" line, Pulse tries to catch up by applying a correction factor to the intended delivery so it actually delivers more.

  2. The image below shows a goal constantly over-delivering and therefore hovering around the upper boundary where the delivery is paused.

    Over-delivering goal braking and pausing

    Braking: when the goal is between the grey "Brake" curve and pink "Brake completely" curve, Pulse brakes the goal in a way that it still delivers, but at a slower pace.

    Pausing: when the goal is above the pink "Brake completely" curve, Pulse completely pauses the delivery and waits for the goal to fall under the pink curve so it can start delivering again.

Daily and hourly goal caps versus Pulse dynamic design

With the Pulse simulation based forecasting approach, which forecasts future available inventory based on historical user traffic and current campaign and account settings, you see whether your campaign is going to deliver as expected or not, this way benefiting from Pulse's dynamic design. For more details, see the Planner.

Using daily and/or hourly caps means that the goal's daily and/or hourly delivery should not exceed the cap, but there is no guarantee it will reach the cap, especially in case of traffic pattern changes. This approach is static, as opposed to Pulse's dynamic design, and implies there is a 100% certainty you are going to have enough inventory to deliver on the cap. Things to keep in mind:
  • If you get less inventory than you needed, you are not going to reach the daily and/or hourly cap, which then leads to wasted inventory.
  • If you get more inventory than you expected, Pulse cannot make use of that extra inventory in a good way. This is why most display ad servers run empty during sudden traffic spikes.
  • Delivery information is re-evaluated at fixed intervals, currently approximately every 5 minutes. This means that regardless of the cap, if the cap is reached within the update window, some over-delivery will occur during that time.
  • Caps should be configured in accordance with Pulse's ideal delivery curve. All impression goals (including quartiles and click-throughs) with an end date in Pulse deliver according to an ideal delivery curve, which means Pulse delivers slightly more in the beginning to safeguard against under-delivery in the end. If your caps are lower than what the delivery algorithm calculates a goal should deliver on a specific hour or day, then Pulse considers the goal to be under-delivering and tries to catch up (apply a correction factor to the intended delivery so it actually delivers more). This also means it reaches the cap very quickly, so the delivery is not evenly distributed during the capped period. For example, Pulse might deliver the capped amount in the first hour of the day, and also deliver over the cap due to the update window, then do the same thing next day, and so on. The image below shows such goal with daily caps and uneven (staircaselike) delivery and over-delivery. The blue "midroll goal aggregated" line visualises how the actual delivery looks like due to the use of daily caps.

    Uneven delivery and over-delivery when using caps

    Taking this into consideration, together with the previous bullet point, uneven delivery and delivery over the cap are expected. The amount of over-delivery that occurs within the update window depends on various factors, such as campaign configuration and site traffic. Higher over-delivery occurs, for example, if the cap is too low compared to what Pulse's delivery algorithm calculates a goal should deliver, you have frontload set to a certain %, and at the same time you are getting more traffic than usual due to popular content.

Currently, in Pulse, you can set the following impression and event (% ad completion or click through) caps, and combine them where applicable:

Cap Type Impressions (normal and sponsor) Share of Voice (normal and sponsor) Unlimited impressions Priority unreserved 25%, 50%, 75%, or 100% Ad completion Click throughs
Total Impression Cap X X X
Daily Impression Cap X X X X
Hourly Impression Cap X X X X
Daily Event Cap X X
Hourly Event Cap X X

For more information, see Add new goal and Goal and goal rules 1.0 requests.