In recent years, data clean rooms have grown in importance to media and advertising companies' businesses. But this year has been "a step-change year where clean rooms became more sophisticated," Therran Oliphant, svp of data and technology at Essence Global, said during the latest episode of the Digiday Podcast.

The (supposedly) impending demise of the third-party cookie and increasing scrutiny from privacy regulators have pressed advertisers, agencies, tech platforms and media companies to adopt data clean rooms as a means of protecting their first-party data while activating it for advertising purposes.

Already a fixture in major advertisers' dealings with tech platforms like Google, Meta and Amazon, this year data clean rooms were a key component of TV upfront ad buyers' and sellers' negotiations. Then, in October, Google announced its Publisher Advertiser Identity Reconciliation program to facilitate advertisers' and publishers' use of clean rooms for programmatic buying and selling. And in December, IAB Tech Lab plans to release its first draft of standards for clean rooms.

Despite all the developments -- or maybe because of the developments -- the data clean room remains an enigmatic aspect of the advertising business because of its broad application.

"There is really no one ultimate application of that data," said Oliphant. "It could be that this particular data might be used for advanced analysis. Or to join data sets together so that a brand could understand more attributes about their user. Or so that they can go to market and activate media against those users."