Why would you exclude an audience from your ad targeting?

An audience is excluded from ad targeting to prevent ads from being shown to irrelevant users or those who have already completed the desired action, such as making a purchase. This helps to optimize ad spend by ensuring that ads are only shown to potential new customers. For example, if you are running a retargeting campaign to encourage website visitors to make a purchase, you would exclude users who have already purchased the product to avoid wasting ad impressions on them. Another example would be excluding your existing customers from a lead generation campaign if the goal is to acquire new customers only.