--- title: "How to Build Retargeting or Exclusion Segments in Web" canonical: "https://hub.freewheel.tv/space/BC/115277904/How%20to%20Build%20Retargeting%20or%20Exclusion%20Segments%20in%20Web" format: markdown --- Overview Retargeting or excluding users who have visited a website (or any pixeled website) is a common use case. Segment Targeting enables the ability to retarget or exclude users based on their prior interactions with a site. For detailed guidelines on retargeting best practices, refer to Retargeting Best Practices . How It Works Follow these steps to create a retargeting or exclusion tag and use it on a site: Create a New Segment Navigate to Trafficking > Segments > New Segment . Complete the Segment Information There are two types of segments to choose from: Advertiser-level segments : These are specific to the selected advertiser. Account-level segments : These are available to all advertisers in the account. Once the segment is created, the tag will be stored under the chosen Advertiser or Account . Save & Generate the Tag Click Save & Generate Tag . Implement the Tag Copy the generated tag and place it on the relevant page. After implementation, click either Save & Close or Save & Continue (if you wish to assign the segment to a Segment Category ). The "Value" parameter is optional and can be used to associate additional data (such as purchase amount or page views) with the user-segment combination. If this isn’t necessary, it can be omitted. View User Count After implementing the pixel tag, you can monitor the count of users within the segment in the Segments table , located under Trafficking > Segments . Target the Segment in a Line Item When creating a Line Item , locate the segment under Your Segments in the Targeting tab of the Create Line Item screen. Email Open Retargeting While segment pixels can be configured for email open retargeting, the success rate of setting the cookie will generally be lower than the email open rate. This is because many email clients, like Gmail, restrict third-party cookies, and email clients such as Outlook do not allow cookies to be set at all. Using a Single Segment Tag to Populate Multiple Segments A single segment tag can be used to add a user to multiple segment keys within the bidding instance. This can be achieved by specifying multiple segment_key parameters within the URL. Example of Multiple Segment Keys: html To specify a value for each user-segment association, include the value parameter in the same order as the segment_key parameters. Example with Value Assignments: If you want to assign a value of 1.5 to buzzkey-1 and 3.6 to buzzkey-2 , use one of the following options: Option 1 : Option 2 : html If some segments are not assigned a value, an empty &value= parameter must be included for those segments to preserve the correct key-to-value order. The number of value parameters must match the number of segment_key parameters. Limitations A user can be added to up to 100 segments in a single associate-segment call. This is a hard limit and cannot be increased. How to Sequentially Target or Exclude Users Who Have Seen an Ad on the Web A common use case is to retarget or exclude a user who has already seen an ad. This can be done in the web environment using the following steps: Create a Segment Navigate to Trafficking > Segments > New Segment . Save & Generate the Tag Copy the generated tag (e.g., https://segment.prod.bidr.io/associate-segment?buzz_key=buzzkey&segment_key=buzzkey-123 ). Add the Tag to the Creative Add the tag URL as a pixel in the creative(s) you plan to serve to users on the initial line item. Target the Segment in a New Line Item On a separate line item, target the segment (e.g., buzzkey-123 ) to retarget or exclude users who have already seen the ad. Web-Only Implementation This method is limited to web environments. For app or CTV environments, segment postbacks must be used instead.