A little over two decades ago brands were innovating with programmatic advertising and ad networks, but that landscape drastically changed as the cookie came along, but now those technologies are marking a comeback. Cookies are fading with the increased prevalence put on privacy which means brands are relying now on probabilistic models to develop the personal experience. However, more research and data are going to be needed to be put in this model so they can respond quickly and accurately, which is a difficult job given how cumbersome data is getting. Moreover, brands are racing to develop ways to track brands across platforms with identity graphs. Marketers need to be clear about their goals and optimize their first-party data if they want an edge in the post-cookie world.