There are a dizzying number of types and sources of customer data, and this is what makes understanding the current data landscape so important. For retention marketing in particular, it is the valuable first-party data that makes it a powerful addition to any online omnichannel strategy. Data is categorized as one of the following: first party, second party, or third party. Understanding the difference in value between different data types is the first step in enabling marketers to extend their ad strategies beyond basic acquisition to include retention. The deep understanding of specific customer interests and behavior provided by first-party data is the critical component of powerful site retargeting, Facebook retargeting, and smart digital advertising.The process where the DMP passes the audience to the DSP, using a feedback loop to optimize performance, is still only really suited for high-level acquisition. As any marketer knows, the key to retention is building personalized customer journeys that inspire customers to keep engaging with the brand, which is where DMPs fall short. This is yet the old Internet, the one-way street of communication.