Publisher Common ID

Publisher Common ID (PubCID) is a privacy centric first party cookie solution. Built with consumer privacy in mind. PubCID does not sync IDs across domains so the IDs your domain generates are yours to share with whom you choose. Because the user IDs generated are site specific, there is no degradation of these IDs over time, improving user match rates. Additionally, latency issues generally caused by multiple call outs to various parties are significantly reduced, improving user experience, viewability and earnings.

Publishers that have implemented PubCID have seen an immediate lift in earnings and improvement in user interaction on their domain. This solution is open source, free to use, and does not require any consortium memberships.

Technical Description

The PubCID plugin supplements the JavaScript by rewriting PubCID as a server-side cookie to accommodate a custom expiration time frame. By default, it only updates cookies that have been generated by other sources and can also be configured to check consent strings and generate IDs directly.

A new rest endpoint is added that returns a 1×1 pixel and to update the cookie. The URL is ‘/wp-json/pubcid/v1/extend/’. The trailing slash is required. This allows caching to be used as long as the endpoint itself is excluded.

Working with Prebid

Requires Prebid.js User Id modules with pubCommonId. Set params.pixelUrl to ‘/wp-json/pubcid/v1/extend/’.

Generating ID Directly

The PubCID plugin can be configured to generate IDs directly from your domain by setting the Consent Function and the Generate Function in the settings of the page as outlined below.

Consent Function – This can be a custom function name, or a function provided by other plugins. It should return true if there is user consent. If omitted, it’s treated as having consent and the consent is derived from other means such as JavaScript.

Generate Function – Specify wp_generate_uuid4, this will return a random UUID.