Walled Garden | Definition
In advertising, the term “Walled Garden” is often used to describe certain super publisher platforms that operate as private ecosystems. These publishers offer advertisers access to their user base for the purposes of marketing their own brands while limiting the detail they share externally on campaign performance and individual users. In essence, advertisers can peer over the “wall”, but they cannot actually enter the “garden.”
These super publishers perform attribution on their traffic independently and are thus called self-attributing networks (SAN). Some SANs include: Facebook, Snapchat, Twitters, Instagram, Verizon Media