Wilkins Media 
Represents out-of-home media companies to ad agencies and advertisers.
http://www.wilkins-media.com/AdSmart Outdoor Advertising
Out-of-home media company specializing in billboards, and auto and fleet ads.
http://www.adsmartoutdoor.com/
Kartik Advertising
India based advertising agency focused on outdoor campaigns in Indian railway and bus shelters.
http://www.kartikgroup.com/
Lamar Advertising Company
Owns and operates outdoor advertising and logo structures. (Nasdaq: LAMR).
http://www.lamar.com/
