A scary version of this is driven home to me when I go to Washington DC and see all of the very expensive billboards at commuter stations near the Pentagon advertising fighter jets and other military equipment.
It scares me every time because they wouldn't be splashing out the big bucks for those billboards if they weren't effective, and I absolutely don't want the military (or any other entity engaging in major expenditures) to be making those decisions based on billboards.
A magazine would be an improvement. I worked in a place where the owners were very susceptible to airport billboard ads.
Every time they came back from a trip, we would brace for change.