Described herein are solutions for improving ad retargeting. For example, described herein are solutions for improving ad retargeting amongst various online marketing channels, such as search engine and native advertising marketing channels. The solutions can include adaptive ad retargeting. Adaptive ad retargeting can be beneficial in that it can solve the problem of ineffectively predicting which search terms to associate with advertising, such as in a more conventional process of selecting search terms in a search engine marketing campaign. Instead, for example, these technologies can identify behavior of individuals who have already interacted with certain advertising online, so that when similar behavior occurs by those individuals or other users, ads can be retargeted to such users effectively according to the similar behavior.