In soviet russia, billboards look at you.

[MaximKamerer]

In advertising these days, the brass ring goes to those who can measure everything--how many people see a particular advertisement, when they see it, who they are. All of that is easy on the Internet, and getting easier in television and print.
Billboards are a different story.

http://news.cnet.com/Billboards-that-look-back/2100-1024_3-6240681.html?tag=cd.top