Ad Selection

Last updated on October 3, 2014

OpenX considers many factors when determining which ad to serve for a given impressionA single display of an ad on a web page, mobile app, or other delivery medium. For deals, impression is a metric to relay the total number of ads that have served. See also billable impression, forecasted impressions.. This topic describes these considerations so that you can better understand why particular ads serve to your ad space, and what is the best approach to setting up your orders and inventoryAd space available on a website or app. The basic unit of inventory for OpenX is an ad unit..

Ad selection is a four step process. OpenX:

  1. Determines eligible line items based on business rules.

    Based on your account structure, OpenX identifies the superset of eligible line items for the ad unitThe smallest inventory component that represents the space on a site where ads display. making the request.

  2. Applies targeting and frequency capping set at the line itemThe primary unit of execution for an order, which represents a specific inventory purchase and the required conditions for ad delivery. level.

  3. Selects a line item based on buying model prioritization.

    OpenX considers the buying models of eligible line items in the following order of priorityIndicates which deal or line item should take precedence in the case that multiple deals or line items are eligible to serve for a given ad request.:

    1. Guaranteed - Exclusive

    2. Guaranteed - Share of Voice

    3. Guaranteed - Volume GoalA setting for guaranteed line items. A volume goal for impressions is used to reach a set number of impressions as soon as possible, depending on the Priority setting for the line item.

    4. Non-Guaranteed

    5. House

    Note: If there is a tie, OpenX applies its tie-breaking logic to determine the winning line item.

  4. Selects an ad from the winning line item.

    After OpenX selects the winning line item, it determines which ad to serve from among active ads in the line item.

This topic applies to Ad Server.