Advertising transparency, in the context of real-time bidding (RTB) on ad exchanges or ad networks, refers to an advertiser’s ability to know the precise websites and locations where their ads are displayed. This principle aims to address viewability challenges and can answer questions that arise during ad delivery. Ad exchanges are committed to transparency with agencies and advertisers to ensure greater clarity. Beyond online advertising, advertising transparency can also encompass how advertising messages are presented to consumers and the clear identification of advertising as such. Obstacles to transparency can arise in various contexts, such as native advertising, influencer marketing, or television advertising. A concrete example of transparency demonstrated by an ad exchange or marketplace could illustrate these principles in action.