Advertisers now have the opportunity to gather demographic information about passengers in cars as they drive by digital billboards, allowing advertisers to target ad copy to the preferences of the passenger's demographic.

SmartSign Media, headquartered in Sacramento, displays ads on interactive electronic billboards on highways adjacent to shopping malls, writes Media Life (via MediaBuyerPlanner). Interactive technology allows advertisers to gather information from the car's passengers based on what station they are listening to, and the ad message can be changed instantly based on the demographic profile of those who listen to that station, including income and shopping habits.

Signs can offer coupons or other special offers to shoppers as they approach the stores, and they can also pull pages off the internet and display them, providing up-to-the-minute content; they can ask consumers to respond via text message to a question posed on the billboard.

Ads are placed on pylons and are considered digital signage centers, allowing them in areas where there may be restrictions on billboards. Eight advertisers can be displayed, in rotation, on a single sign, and advertisers can select locations or buy the network.

SmartSigns are available in Atlanta, Las Vegas, New York City, and 15 California markets.