OOH Audience Measurement Explained: From Footfall Counting to Impression Data

One of the most common questions from advertisers new to out-of-home advertising is: how do you actually know how many people saw my billboard? Unlike digital advertising, where every impression can theoretically be tracked to a device, OOH advertising reaches people in physical spaces. Measuring that exposure requires different methodologies. This guide explains the four main OOH audience measurement approaches used across Southeast Asia.

Method 1: Traffic Count and Pedestrian Flow Data

The most basic OOH audience measurement method, traffic count, uses historical vehicle or pedestrian flow data measured at each OOH location to estimate the number of opportunities to see (OTS) that a screen or billboard generates in a given period. Traffic counts are typically conducted by the media owner or by an independent measurement body and are expressed as average daily vehicles (ADV) for roadside sites or average daily pedestrians (ADP) for pedestrian environments. Traffic counts give you a top-line reach number, but they do not account for viewing angle, dwell time, or visibility.

Method 2: Mobile Device Data and Geofencing

Increasingly, OOH audience measurement in Southeast Asia uses anonymised mobile device location data to estimate the number of unique devices — and by inference, unique individuals — that passed within the viewshed of an OOH screen during a campaign period. Mobile measurement tools segment the device population by demographic characteristics derived from app usage and behavioural data, enabling audience composition analysis alongside reach estimates. This is significantly more accurate than traffic counts for audience segmentation, though it relies on device sampling rates and proximity assumptions.

Method 3: Eye Tracking and Visibility Studies

Eye-tracking studies measure the actual visual attention directed at OOH advertising by a sample of consumers. Respondents wear lightweight eye-tracking glasses during normal daily activity, and researchers analyse the resulting data to determine what proportion of people passing an OOH location actually looked at the advertising, and for how long. Eye-tracking studies are expensive and impractical at scale, but they provide the most accurate measure of true attention — and the results are consistently used to calibrate visibility adjustment factors for traffic count and mobile data methodologies.

Method 4: Post-Campaign Brand Lift Research

The most commercially meaningful form of OOH measurement, brand lift research, surveys a sample of consumers who were exposed to a campaign and compares their brand awareness, consideration, and purchase intent to an unexposed control group. The resulting brand lift data quantifies the actual attitudinal change produced by the campaign — not just who had the opportunity to see it, but how it changed their perception of the brand. Brand lift research is the standard measurement approach for large-budget OOH campaigns and is available through Moving Walls Market’s measurement partnerships for campaigns above a minimum threshold.

Download our comprehensive OOH measurement guide for detailed methodology explanations, market-specific benchmarks, and a framework for choosing the right measurement approach for your next campaign.