The Dimension Priority Bid Model component allows you to take control of the way your campaign delivers impressions. You can specify the order in which a campaign should attempt to deliver those impressions across the Creative, Location, or Inventory dimensions that your campaign is targeting.

Dimension Priorities are one of the three Bid Model components that you can manage for your campaigns. Refer to Bid Modifier overview and Spend Ratio overview for more details on the other ways that you can apply Bid Model settings.

All advertisers can apply Dimension Priorities to a campaign; however, a campaign must meet each of these conditions before it becomes eligible.

Dimension Priority establishes a sequential order of bidding. When you assign priorities to a set of dimensions, you choose the order in which a campaign is executed. These priorities can range from 1 to 10, with smaller numbers indicating a higher priority, and larger numbers indicating a lower priority.

Apply Dimension Priorities to dimensions within a single dimension category, or apply them to multiple dimension categories.

Dimension Priorities follow a waterfall method when they’re assigned to dimensions that fall within the same dimension category. The campaign fills as much budget as possible on the highest-priority dimension you assigned, then assesses Daily spend pacing.

In certain cases, this means that the campaign will only spend on the dimensions that you’ve assigned to Priority 1. However, if the pacing check indicates that the campaign is pacing behind, then it’ll begin serving on the next-highest-priority dimension(s).

Once the system begins serving impressions for a lower-priority dimension, it continues to do so throughout the campaign’s duration or until its budget is depleted.

You can assign the same Dimension Priority to more than one dimension. The Bid Model will treat any dimensions featuring the same priority equally during campaign execution.

In this example, an advertiser creates a campaign and targets the following five creatives:

Each of the creatives are relevant to the advertiser’s campaign, but they’d like to specifically prioritize Creative A, Creative D, and Creative E. They only want to spend campaign budget on Creative B and Creative C if the campaign can’t fulfill its entire budget by serving ads for the other creatives.

The advertiser defines a priority of 1 for Creative A, Creative D, and Creative E; and of 2 for the campaign’s less-essential creatives.

*The non-prioritized creatives (Creative B and Creative C) are captured in Others.

The campaign will serve impressions for exclusively Creative A, Creative D, and Creative E if it achieves the expected daily spend. In cases when the expected daily spend isn’t met, the campaign will serve impressions to the creatives captured in Others (Creative B and Creative C) to fulfill the budget.

In this example, an advertiser creates a campaign and targets the following five creatives:

Each of the creatives are relevant to the advertiser’s campaign, but they’d like to specifically prioritize Creative A, Creative D, and Creative E. They only want to spend campaign budget on Creative B and Creative C if the campaign can’t fulfill its entire budget by serving ads for the other creatives.

The advertiser defines a Dimension Priority of 1, 2, and 3 for Creative A, Creative D, and Creative E, respectively; and of 4 for the campaigns non-prioritized creatives.

*The non-prioritized creatives (Creative B and Creative C) are captured in Others.

The campaign will serve impressions for exclusively Creative A if it achieves the expected daily spend. In cases when the expected daily spend isn’t met, the campaign will serve impressions to Creative D (Priority 2), then to Creative E (Priority 3), and finally, to the creatives captured in Others (Creative B and Creative C, Priority 4) to fulfill the budget.

As with Dimension Priorities for a single dimension category, Dimension Priorities follow a waterfall method when you’ve assigned them across more than one dimension category. The Bid Model’s approach to filling as much budget as possible on the highest-priority dimension is also the same whether you define priorities for a single or multiple dimension categories.

Single- and multiple-dimension Dimension Priorities differ when it comes to the way they choose which dimensions they can serve impressions on. If you define Dimension Priorities across more than one dimension category, the Bid Model applies “AND” logic to evaluate incoming ad requests. This means the campaign will only bid on an ad placement when every rule you’ve defined is satisfied. Refer to Example: Dimension Priority - Multiple dimension categories for more information on how it works.

These rules can change as the campaign progresses based on how the campaign performs during pacing checks. Pacing performance determines the specific dimension(s) for which the campaign can serve impressions. Refer to Daily spend pacing for more details on how often pacing checks are performed and their impact on your campaign’s Bid Model settings.

You can assign the same Dimension Priority to more than one dimension, and to more than one dimension category. The Bid Model will treat any dimensions featuring the same priority equally during campaign execution.

In this example, an advertiser creates a campaign and targets two publisher categories:

The campaign also targets the following four ZIP codes:

The advertiser defines the following priorities for these dimensions:

AND

The campaign initially serves impressions for Priority 1 dimensions across both the Locations (ZIP Codes) and Inventory (Publisher Categories) dimension categories.

In this example, the campaign will begin serving impressions for exclusively ad opportunities that are either:

A few days later, a pacing performance check reveals that the campaign will ultimately underspend if it continues serving ads for only Priority 1 dimensions. The Bid Model begins serving ad impressions for all Priority 1 dimensions and Priority 2 dimensions to help ensure pacing performance.

With Priority 2 dimensions enabled, the campaign begins serving impressions for exclusively ad opportunities that meet any of these conditions:

The campaign will open up serving for lower-priority dimensions (Priority 3) if future pacing performance checks identify that the campaign is at risk of underspending. This campaign will never revert to serving ads for exclusively the Priority 1 impressions at any point throughout its remaining duration.

The steps you’ll follow to add or edit a Bid Model setting will differ based on the dimension category for which you’d like to apply the Dimension Priority, Bid Modifier, or Spend Ratio.

Refer to the dedicated resources linked below to learn how to apply a Dimension Priority or another Bid Model component based on the dimension category.

The Bid Model automatically checks pacing throughout the campaign’s duration to help ensure optimal spending. The campaign’s pacing performance impacts the way in which the Dimension Priorities you defined for the campaign are applied.

These pacing checks include comparing the campaign’s total spend to the expected spend up to that point in the campaign’s duration. The campaign is considered to be pacing behind if its total spend is less than 90% of the expected spend. This triggers the campaign to serve on the dimensions that are one level lower in priority.

The campaign applies the same logic throughout the campaign, and continues to enable the next-highest priority as needed to help ensure appropriate pacing and, ultimately, full-budget spend.

You’ll know that serving is enabled for a dimension when the circle next to it in the Priority column changes from gray to green. This indicates that ads are being targeted for that dimension based on the latest pacing performance check.

The frequency of pacing checks increases based on how soon the campaign is ending. Campaigns with assigned Dimension Priorities follow this pacing-check schedule.

A campaign with a 15-day duration follows the pacing-check schedule shown below:

The campaign initially serves impressions for only the dimensions that are assigned Priority 1. During a pacing check, the Bid Model identifies that the campaign’s pacing has fallen below 90% of the expected spend. The campaign starts serving on all dimensions that the advertiser assigned a Priority 1 or Priority 2.

Spend Ratio is a Bid Model component that allows you to take control of your campaign’s spending pattern. You can specify how much of a campaign’s total budget you’d like to allocate to each Creative, Location, or Inventory dimension that your campaign is targeting.

Refer to Spend Ratio overview for more details, and review Example: Flexible Spend Ratio and Dimension Priority for an illustration of how these two Bid Model components work when both are applied to the same dimension.

Others appears in the Bid Model table any time you choose to apply Dimension Priorities to only certain dimensions in a dimension category. Others aggregates all of the items you’re targeting in the same dimension category that don’t have a Dimension Priority applied to them. It may also include items that your campaign isn't directly targeting, but that appeared in its serving data within the past three months.

You’ll first apply the desired Dimension Priority percentages to those dimensions. Then you’ll use the Others field to only spend campaign budget on the other items you’re targeting in the same dimension category if it can’t be filled by targeting the prioritized ones.

Refer to the example in this article’s Dimension Priority - Single dimension category section for an example of how the Others field works.