The document discusses how the ID Graph enables people-based marketing by centralizing customer data from multiple sources. Marketers currently struggle to target audiences across channels as consumers use multiple devices and online identities. The ID Graph addresses this by linking identifiers such as mobile IDs, cookie IDs, email IDs and social IDs to create a unified customer profile. This comprehensive view allows marketers to better understand customer behavior and interests, and target them more effectively with personalized, cross-channel messaging.