Allowlists and Blocklists are the rules you establish to determine which ad impressions a campaign is eligible to bid on. These rules relate to various campaign elements (such as Locations, Device IDs, Audiences, and more. For example, you can choose which relevant audiences you’d like to show your ad to, and which ones you’d like to prevent from seeing the ad, by adding those audiences to an Allowlist or Blocklist. Note that you may see Allowlists referred to as “white lists” or “target lists” and Blocklists referred to as “black lists” in other DSPs.

While customizing a campaign with Allowlists and Blocklists is essential for tailoring a campaign, these elements should be reserved for only the non-negotiable rules you’d like to apply to the campaign. Refer to Impact on reach and impressions for more information on scale considerations.

You’ll apply targeting criteria to a campaign when you want to define who you're willing to serve the ad to based on a specific set of criteria. For example, you can choose to only advertise to users who are browsing on a particular device, located in a particular geographic region, and belonging to a particular audience.

Your targeting settings get added to an “Allowlist” for each relevant dimension category.

You’ll apply blocking criteria to a campaign when you want to avoid showing your ads to users based on a specific set of criteria. For example, if you’re building an awareness campaign, you might want to prevent users who previously converted on your website from seeing the ad by adding a Retargeting audience to a Blocklist. You can also choose which sites or apps you’d like to avoid in order to maintain the brand’s image or exclude irrelevant inventory.

Your blocking settings get added to a “Blocklist” for each relevant dimension category.

Note that a campaign’s Allowlists and Blocklists are assigned an “OR” relationship, meaning that they work independently for each dimension. Allowlists and Blocklists are specific to each campaign element such as Audience, Location, Inventory, and more. This means that you can, for example, exclude a certain audience and include a certain site domain.

With an “OR” relationship, a campaign won’t bid on an impression if it matches any one of the exclusion criteria included in a Blocklist. For example, you can’t block one user who is located in New York “AND” browsing a particular site domain. The campaign will block any user who is either located in New York “OR” browsing a particular site domain.

Example Blocklist:

Allowlists follow a similar logic, but will include rather than exclude the items you’ve specified. Using the same example, you can’t target one user who is located in New York “AND” browsing a particular site domain. The campaign will bid on an impression if it matches either one of these inclusion criteria.

Allowlist rules differ slightly from Blocklist rules. If you target certain campaign dimensions, then all other dimensions in the same dimension category are excluded. For example, if your campaign targets New York and California, it’ll only bid on New York impressions or California impressions. This means that all other Locations are effectively blocked from the campaign.

Example Allowlist:

You can create an Allowlist or Blocklist for each dimension category, or element, listed below.

* Refer to What are Blocklisted Inventories? for more information on inventory Blocklists.

Allowlists and Blocklists help ensure that every marketing dollar goes toward the strategies that are the most likely to reach your target audience—but they also limit the number of impressions that you can bid on. This can put your campaigns at risk of spending in full.

Forecasting and reporting metrics provide a sense of scale to help you determine whether you can spend your campaign budget in full and achieve campaign objectives. Leverage your preferred tools in the Campaigns, Planner, Reports, and Insights apps to help right-size your campaigns’ Allowlist and Blocklist strategies: