he outdoor advertising industry had lacked an empirical measurement device to track the effectiveness of outdoor ads. Nielsen Outdoor claims to have developed the first such device to measure outdoor advertising audiences using portable Global Positioning System (GPS) technology. Nielsen Outdoor tested the device in Chicago by asking 850 randomly-selected respondents to carry pager-sized GPS devices called Npods (Nielsen Personal Outdoor Devices) for nine days to track their movements throughout Chicago. The data was then converted into measures of exposure to outdoor advertising messages based on proximity and direction of travel with respect to the outdoor panels.

The results reveal that men in the 35-54 age group have the highest exposure to outdoor advertising, particularly among the upper-income, full-time employed audiences. The results also showed that the average adult is exposed to 40 outdoor advertising messages per day, much less than the number of messages on electronic media. This means that there is less clutter in the outdoor medium, giving audiences more time to observe the messages displayed.... more