I created a billboard to get flowers for Vesnali. I've noticed in the billboard management page it says it has 0 clicks, but I am pretty sure I've gotten flowers from people while I was asleep and not posting in the Vesnali boards. So I'm guessing people have been clicking the ad, even though the site says it has 0 clicks.
Same thing happened to me for both Vesnali and Masq. My guess is that the clicks are actually happening to the "flower Marcus/invite Marcus to a dance" buttons that appear alongside the billboards, and not the billboards themselves. If you hover over existing billboards in the forums, the image itself is not a link. So, technically nobody clicked the billboard.
Still, I would love to know how many people clicked the flower/dance/etc. link so that I can determine if paying for a billboard is worth it.