The IAB Tech Lab introduced standards earlier this month that aim to make the process of declaring an identifier more transparent—a hot-button issue that has been dividing the adtech community for months.
Earlier this year, the buy side called out publishers and their tech partners for using deceptive practices to identify audiences.
At the center of these accusations is ID bridging, where a publisher will link a user in a cookieless environment, like Safari or iPhone, to who they are on Chrome. A demand-side platform might think that it is bidding on a Chrome user with a cookie, but it is really bidding on a user whose identity is inferred. DSPs argue that this undermines campaign performance and can lead to fraud.
Many on the sell side rely on these techniques to monetize audiences that wouldn’t ordinarily be addressable. They counter that DSPs should be aware.
To help clear up the mess, the IAB Tech Lab has provided a forum for these debates since February.
Those conversations have resulted in new protocols, first described in an IAB Tech Lab blog post May 8 written by Mike O’Sullivan, co-founder of metadata firm Sincera. The new specs are in public comment until June 10.
The new protocols
The IAB proposed an update to a standard that was implemented in 2022.
That standard prompted publishers to use the Extended Identifiers (EID) field in a bid request to identify the use of alternative IDs, such as UID2, RampID or ID5, using code read by the DSP. The typical place for DSPs to view the use of identifiers in the bid request—which, up until recently, mostly meant third-party cookies—was a separate field called the buyeruid field.
With the May 2024 update, publishers can only place identifiers in the buyeruid field that are specifically agreed upon by the buyer and seller. In practice, this means that the buyeruid field is reserved for cookies, and the EID field contains all other alternative IDs.
Confusion has arisen when sellers place a non-cookie solution, like ID bridging, in the buyeruid field. Under the new standard, this is fine, as long as the buyer and seller explicitly agree on using this ID.
The protocol also includes new ways for publishers and their tech partners to use the EID field to specify if and how they’re using ID bridging.
“We are now clarifying that buyeruid is intended as an explicit mapping as agreed upon by buyer and seller,” said Anthony Katsur, CEO of IAB Tech Lab. “There were a lot of assumptions on both side of the ecosystem.”