Who is this for?

I've been seeing these billboards all around town for months:

Who is this aimed at? Does anyone really drive past these things and think, "I gotta get me some Canadian whisky!"? Well, I guess some people might - so is this sign just one big reinforcement for alcohol addiction?

I guess my thinking applies to all billboards that are not on major highways. I can see the return on promoting a McDonald's, or a motel, to people driving down the interstate. But these city-street billboards seem to me to be a totally ineffective way of getting your message out.