I was in Galway today when i saw a small plane towing a banner along at low altitude. I've only seen one of these before at an open air concert in Ireland, the others i've seen were abroad!
I don't really understand Aerial Advertising, most of the time the banner has been to far away for me to make anything out and i see it as a bit of a hazard. Can you imagine the banner causing the aircraft to ditch in a highly populated area like a concert or other event? Or even the banner coming lose and falling on a unsuspecting crowd?
Blimp Advertising would probably be worse! Imagine in low viability conditions a light Aircraft colliding with one? Yikes!
I suppose if you have money to advertise that way you have enough to cover all eventualities such as things going wrong.