The advertisements may be "Always on", but perhaps no one wants to buy them

CBS/Decaux transit shelter advertisement, Vancouver, British Columbia

Every now and then I see these transit shelter advertisements around Vancouver. And what message should I take from these?

I do like the "Always on", a dig at electronic media. But if CBS could sell the space then would I ever see these posters? I think not. The people buying advertising space are probably not swayed by this sort of message. They care about demographics and the number of eyeballs that see these posters each day.

But better to advertise your own services that leave the frame empty.