In the digital advertising ecosystem, effective targeting is crucial for the success of campaigns. The shift to first-party data and advanced AI technologies has revolutionised digital media buying. One of the highlighted approaches is lookalike modelling, or modelling based on shared characteristics using AI. This approach allows brands to target their advertising campaigns more precisely to the right audiences with a much higher likelihood of liking a brand. In this blog post, I will explain how digital media buying is done using first-party data and lookalike modelling using AI and show a practical example.