Cookie syncing

What is cookie syncing?

Cookie syncing helps match user information recorded by cookies on different platforms in order to have a common understanding of the user. Here is an example: When a user lands on a website, every adtech partner involved in an adtech transaction, such as a supply-side platform (SSP), demand-side platform (DSP), data management platform (DMP), etc., uses cookies to record user information in separate cookies. Since cookies are domain-specific, the information recorded by one partner cannot be accessed by another. When the same user lands on a different website using the same adtech platforms, they cannot re-identify the user.

Cookie syncing is the process of synchronizing cookies across platforms to share information about a single user to re-identify them across all the platforms in the future. This also enables placing the right bids and delivering relevant ads to users.

How does cookie syncing work?

Let’s try to understand cookie-syncing through an example.

Olive visits a website abc.com that uses AdX as its monetization platform.
AdX sets up cookies on Olive's browser to track their information and identifies them with the ID Olive123.
AdX's DSP considers them a new user and creates a new ID, say Olive456.
The DSP bids on the user's (Olive's) impression when the auction takes place.
However, the bid is very low.

Olive’s visits another website xyz.com that also uses AdX.
AdX re-identifies Olive using the ID Olive123.
AdX collaborates with its DSP and they both sync their cookies (Olive123 and Olive456).
The DSP now identifies Olive as the same user who visited abc.com.
The DSP bids higher this time as it knows Olive’s interests.

All this was possible through the process of cookie-syncing between AdX and the DSP.

Benefits of cookie syncing

The concept of cookie syncing helps advertising platforms identify users, their behavior, and their interests. This helps create in: