The buy side, represented by tech platforms, is accusing publishers and their tech partners of deceptive practices within the IAB Tech Lab discussions. This tension arises from alleged strategies, driven by signal loss, to identify audiences in cookieless environments. Digital advertising's demand-side platforms (DSPs) claim that sell-side platforms (SSPs) are utilizing covert techniques, such as ID bridging, without informing the buy side, potentially affecting marketing efficacy.

As browsers like Safari, Firefox, and Chrome phase out third-party cookies, sell-side platforms resort to probabilistic identifiers and techniques like ID bridging, linking users in cookieless environments to their identities on other platforms. The lack of transparency between DSPs and SSPs leads to accusations of fraud and raises concerns about the precision and privacy safety of these identification methods.

The IAB Tech Lab is actively addressing these issues within the Programmatic Supply Chain Working Group, aiming to enhance transparency and disclosure. However, the dispute highlights a communication gap between business and technical teams on the buy side, potentially impacting conversion tracking and frequency capping.

Buyers express concerns about the privacy ethics of ID bridging and other probabilistic techniques, emphasizing the need for legitimate and privacy-safe alternatives. The tension underscores the challenges posed by the deprecation of third-party cookies and the ongoing efforts to identify audiences without compromising privacy or accuracy.