See unique user ID.

Content on a website that was posted by users and not a centralized publisher. This includes social media posts as well as blogs wikis podcasting images videos audio files and other forms of media created and posted by users of an online system or service. Some sites support user content through advertising. Others are supported by donations subscription fees or a combination of methods. Examples of sites that emphasize or are built around user-generated content include Tumblr Facebook Twitter Instagram Pinterest Wikipedia YouTube Vine and SoundCloud.

A pixel used to synchronize user IDs assigned by different parties during an auction generally to apply frequency recency and other decisioning data. See also user ID mapping.

Each buyer and seller may assign their own different IDs to a user. Without knowing that Seller S's user ABC is the same as Buyer B's user 1234 it is impossible for B to value an impression from S. To allow for attribution and valuation different parties must synchronize their IDs by mapping one ID to another.

See unique user ID.

A place where data about a user is stored. In online advertising this often refers to a user's browser cookie. Sometimes certain user data may be stored server-side for a limited period of time. This data is periodically expunged from server records in order to prevent it from drastically slowing server function and does not contain personally identifiable information (PII).

Information about users that makes them more valuable to advertisers. User data can include age gender location intent to purchase demographics psychographics wealth past purchases and more. User data is generally associated with a UUID found in a cookie rather than any personally identifiable information. User data is distinct from contextual data. Often used interchangeably with segment data and audience data.

This usually refers to a browser application. For example Mozilla 5.0 is a specific user agent.

A target customer for advertisers. The person browsing the web who will see an ad.

Type of inventory:Unreserved

Pricing: Fixed

Participation:One-One

Individual users as represented by a unique user ID. A unique user ID is not associated in any way with personally identifiable information (PII) so it cannot identify a specific unique individual. Also an individual may be associated with multiple user IDs due to clearing browser cookies or using multiple browsers and multiple devices. Additionally for mobile devices a unique user ID may be associated with multiple device IDs (for example Apple IDFA OpenUDID and others). See reach to learn more about individual users/user IDs.

Also sometimes called a UUID. A unique anonymous user ID for a given user profile that may be stored in a user's browser cookie and/or in the a server-side cookie store. Ad traffickers are not permitted to associate these IDs in any way with personally identifiable information (PII) and user IDs do not necessarily equate to a unique individual. An individual may also be associated with multiple user IDs due to clearing cookies or using multiple browsers and multiple devices. Additionally for mobile devices a unique user ID may be associated with multiple device IDs (for example Apple IDFA OpenUDID etc.).

User interface

See user-generated content.