Audience Reach Measurement Guidelines

The goal of the IAB and the entire digital advertising industry is simple: to achieve transparency in audience counts and to revise out-of-date methodologies. For an industry that is committed to delivering accountability, integrity in audience measurement is a fundamental necessity.

The IAB believes that all companies involved in audience measurement should be audited for their processes. These audits are intended to establish the source of any measurement discrepancies and to find potential solutions.

All measurement companies that report audience metrics have a material impact on interactive marketing and decision-making. Therefore, transparency into these methodologies is critical to maintaining advertisers' confidence in digital advertising, particularly now, as marketers allocate more budget.

Download the IAB Audience Reach Measurement Guidelines, Updated August 2013

Scope and Applicability

The recommendations established in these guidelines provide the detailed definitions for measurement of Audience Reach related to Internet-based content or advertising (also herein referred to as “unique” measurements), including appropriate controls, filtration procedures, and disclosures associated with this measurement. Also included in these guidelines—because of the closely related processes involved in measurement—is supplemental guidance for Visits and Time Spent. These guidelines are intended to cover online browser or browser-equivalent based Internet activity. Additionally, any emerging technology utilizing standard HTTP protocols will be covered by these guidelines.

This document is principally applicable to online publishers, ad serving companies, syndicated measurement organizations and auditors and is intended as a guide to accepted practice, as developed by the Interactive Advertising Bureau (IAB) and the Media Rating Council (MRC). Additionally, Advertisers and media planners and buyers at advertising and marketing gencies can use this document to assist in determining the quality of audience reach measurements.

This document is intended principally to guide the definition and application of measures that are to be used for commercial, revenue-generation purposes, and not necessarily those that may be developed and used for other internal or related non-commercial uses. In addition, it should be noted that where references are made within these guidelines to research studies that are required to develop and support data adjustment procedures and similar calibration methods, these do not necessarily need to be conducted by the measurement organization itself. Indeed, particularly in the case of smaller organizations, such studies may be cost or procedurally prohibitive, and in such cases the organization may rely on relevant work that has been done by others (for instance, by syndicated research providers or ad serving vendors, or large measurement organizations, including but not limited to syndicated audience measurement organizations). However, in all cases, the measurement organization must clearly disclose the details of such supporting empirical research, as well as a clear and defensible rationale as to how the referenced study is relevant to the specific case of the property measured.

These guidelines, along with the others that have been developed by the IAB and the MRC, are based on certain foundational principles, which are summarized as follows:

  • Client-Initiated Counting is crucial. These guidelines rely on the central concept that counting should occur on the client side, not the server side, and that counting should occur as close as possible to the final delivery of an ad to the client.
  •  Filtration procedures are necessary to ensure that non-human activities (for example, known or suspected robot/spider originating transactions) are excluded from measurement counts.
  • Caching must be appropriately accounted for to ensure that content not actually delivered to a client is excluded from counts.The contribution of Internal Traffic to a web site should be excluded from counts, if material, and disclosed to data users. 
  • Transparency to data users is a paramount goal of these guidelines. Appropriate Disclosures must be made to users concerning the measurement methodologies employed. Appropriate Disclosures also includes the proper labeling of measurement metrics as defined in this Guideline.
  • Accountability (record keeping and transaction legitimacy) should remain the purview of the measuring/selling organization and not be delegated exclusively to transaction partners that help facilitate completion of measured transactions. Selling organizations should keep necessary records and evaluate transaction partners for legitimacy, to the extent reasonable.

Download the IAB Audience Reach Measurement Guidelines, Updated August 2013