The term walled garden is used to describe any type of closed platform, system, or technology where access to or use of that platform, system, or technology – or the data held within it – is tightly restricted by its owner/operator. In digital advertising, the term is often used when discussing the market’s three biggest players: Google, Facebook, and Amazon.
User data is key to running efficient, targeted ad campaigns, and these three companies gather vast amounts of data on users while they are logged in to their sites/apps. To maintain their market share, each company keeps that data to themselves within a closed system (a walled garden), and advertisers must use each company’s proprietary system to run campaigns and take advantage of that user data.
In digital advertising, there are a number of ways in which publishers compete with these dominant players. For example, adtech players can create a walled garden by combining a supply-side platform (SSP), a demand-side platform (DSP), publishers, and all the technologies and data connected to these entities. If a buyer is interested in the publisher inventory that is included in such an alliance, they can only access it through the walled garden.