Off-network impressions refer to instances when your ad is seen (impressions) on a website other than your own (off-network). These impressions are delivered by what is known as a “display network.” The most common display network is Google, which contains a group of more than 2 million websites, videos, and apps with display space where your ad may appear. Facebook is also a common channel for off-network impression delivery.
Websites in the display network have designated banner and sidebar space where your ad may appear, based upon your audience identification. These ads can be served through two primary audience identification methods.
Display Network Ads
Display network ads are delivered based upon targeting methods that you define, such as keywords and interests. These are not necessarily prospects who have been to your website or have any awareness of your brand.
Example
A veterinarian searches for canine pain management on Google. Later, when she visits cnn.com to read the latest headlines, she is served an ad for your e-book on pain management.
Retargeted Ads
These ads are delivered to only those who have visited your website and been cookied. You may define rules and inclusion and exclusion criteria for these campaigns in your audience development tools.
Example
A prospect visits your website looking for a specific product and leaves without buying. When they go to facebook.com, they see an ad for the product they were just browsing on your website.