A key vulnerability of real-time bidding is that while only one advertiser wins the auction, all participants receive the data. Indeed, anyone posing as an ad buyer can access a stream of sensitive data about the billions of individuals using websites or apps with targeted ads. That’s a big way that RTB puts personal data into the hands of data brokers, who sell it to basically anyone willing to pay.
RTB doesn’t just allow companies to harvest your data—it also incentivizes it. Bid requests containing more personal data attract higher bids, so websites and apps are financially motivated to harvest as much of your data as possible. RTB further incentivizes data brokers to track your online activity because advertisers purchase data from data brokers to inform their bidding decisions.