The problem with billboard advertising is that it's hard to know who is looking at the sign and therefore difficult to analyse its effectiveness in reaching a specific target audience. A high-tech solution from "E-Board" specialists Alaris Media Networks has arrived in the form of a monitoring system incorporated into an LED sign that profiles passing commuters according to the radio station they are listening to and adjusts the ad on display according to real-time analysis of this information.

The MOBILTRAK units will automatically collect radio listening data so the research is passive and unobtrusive for the consumer as well as providing the advertiser with feedback that can be immediately acted upon. A qualitative profile of the people who drive past the sign is also provided, canvassing where they shop, income levels and television viewing behaviour among numerous categories based on listener profiles that are in turn derived from detailed consumer surveys undertaken by the radio stations.

Currently in use in California, the billboards will also communicate with each other in the near future according to Alaris. The goal is for MOBILTRAK units on one section of freeway to relay data to billboards further down the road so that they can display the most appropriate ads to upcoming traffic.