Resolve line item over- or underdelivery
Keep in mind that if you see that a line item is underdelivering, you don’t necessarily need to worry. It may be that there are other competing line items taking up impressions in the beginning of the line item’s run and it will catch up later. You can always run a forecast from within a line item to check and see if there are still enough impressions for your line item to reach its goal by the end date. (See View a list of competing line items to learn how to see how many impressions are available to a line item.).
So what do you do if a line item is underdelivering, and after running a forecast you realize that DoubleClick for Publishers is not expecting it to reach its impression goal by the end of the campaign?
What we recommend
Underdelivery happens when there aren’t enough available impressions for a given line item. Here are a few things you can try to prevent underdelivery:
Extend the line item’s end date so that it has more time to reach its impression goal.
Remove frequency capping so that you’re no longer capping impressions per user.
Make the line item targeting more broad, which opens up more available impressions. For example, if your line item is targeting very granular key-values that don't receive a lot of traffic, or is targeting a narrow slice of your inventory, you could target key-values or ad units that receive more traffic.
Why shouldn't I just increase the line item's priority?
One common response when seeing an underdelivering line item is to change the line item type so the line item is prioritized over other competing line items. For example, you can switch a standard low line item, which has a default priority of 10, to a standard high line item, which has a default priority of 6. Because the line item’s priority is the number-one thing that the ad server looks at to determine which line item will serve to a given ad request, it’s true that increasing the priority will result in your line item getting more impressions. The problem is that now other competing line items will underdeliver and you’re locked into a cycle of manually changing line item types all across your network to respond to underdelivery. This is extremely inefficient, and in many ways defeats the purpose of having an ad server. Also, increasing the priority of your line items may cause your colleagues’ line items to underdeliver.
Why shouldn't I set the line item to deliver as fast as possible?
Another common response to underdelivery is to change the "Deliver impressions" setting to "as fast as possible". Changing this setting won't put the line item back on track to meet its goal; that is, it won't allocate more impressions to an underdelivering line item. It'll just remove the ad server's hourly or daily cap and use up all of the line item's impressions sooner. For example, if you tell the ad server you want a line item that’s running for 10 days with a goal of 10,000 impressions to serve evenly over the course of the campaign, it will try to serve about 1,000 impressions a day and, once it’s hit that daily delivery goal, it won’t serve again until the next day. When you set deliver impressions to as fast as possible, you just remove the daily cap, so all of its available impressions could be used up on the first day.How should I minimize underdelivery?
It is imperative that you always forecast and approve an order before signing a contract to ensure that you have enough impressions available to meet the advertiser’s goals and that you’re reserving those impressions so that other advertisers can’t use them. If everyone in your network is forecasting properly and only booking the number of available impressions, you will be able to greatly minimize the amount of underdelivery you experience. However, if you do still run into underdelivering line items occasionally, please do not adjust the line item type in response. Many of our most successful clients have internal rules stating that a trafficker needs executive-level approval if they’re going to change the line item type. We recommend implementing similar rules in your ad operations group as well.
For more in-depth information, see the ad selection white paper.