Understanding Index and Composition

The Quantcast Platform allows you to view insights and target advertising campaigns based on predefined audiences. You can build audiences based on the general internet population, pixels placed on your website, or offline data you have uploaded to the platform.

Two indicators, Index and Composition, are used across all parts of the Quantcast Platform to help you understand your audience. In Audience Planner, these two indicators can help you get a view of your audience as you build it.

Index

The Index metric compares your audience size against users within the same segment/category across the Internet. 

Across all segments, the US average index is represented as 100. If a segment has an index higher than 100, your audience is more likely to be within that segment compared to the US average. Inversely, if a segment has an index lower than 100, your audience is less likely to be within that segment.

In the example above, we are looking at an audience under the Education category. The Grad School segment shows an index of 115. That means that this audience is 1.15x more likely to have a Grad School education when compared to the US average.

Composition

The Composition metric shows the likely percentage your audience represents for segments that fall within a given category. Composition will always equal 100% for each category (e.g.,s Gender) based on your audience size.

In the example above, we are looking at the likely Gender category of an audience. The composition of the audience leans more towards the Female segment, taking up 52% of the total audience size.

For definitions and use cases, click on the Info icon.

To learn how to build an audience, read Create a New Saved Audience.