Outside of buying ad space on the MTA, I can't think of anything else to do.
MTA?
I would assume that that means, "Metro Transit Authority."
So like the either the New York subway system or buses?
Funny thing that, a lot of the advertising boards (well the ones like TV screens that change every 20 or so seconds) on the London Underground have the CBS logo on them, not sure if they own the ad space or actually make the boards themselves though.