How OpenX Tracks User Activity

Last updated on July 20, 2016

For most customers, OpenX operates under a domain that you control. This means that any cookies set by the ad server are set on your domain instead of an OpenX-owned domain, and in the case of single-domain publishers, these cookies are then treated as first-party cookies, which most default browser security settings allow. A recent trend for new browser versions is to block, by default, third-party cookies.

For managing any type of per-user activity, including frequency capping, conversion tracking, and audience segmentation, OpenX employs a single cookie to uniquely identify a given user on a given browser, across multiple ad requests. This cookie (either OX_u or i, depending on the domain used to fetch ads), contains a unique value, but contains no personally-identifiable information. Any data stored on OpenX servers, which is required to support features like frequency capping and segmentation, refer to this unique user id.

When a user opts out of tracking, OpenX does not remove or alter their identification cookie. This cookie must be maintained to continue to support frequency capping and other features unrelated to any sort of behavioral tracking. Instead, OpenX employs a separate opt-out cookie.

If you are using OpenX Ad Exchange, behavioral targeting by Ad Exchange buyers is also disabled for users who have opted out.