If you advertise for a specific audience, you certainly expect this group of people to utilize your services or buy your products.
But not the "Touristikgemeinschaft Heilbronner Land", a tourism association for the area around Heilbronn in Southern Germany, which now advertises on a rocket - for a knocked-down price of 4000, - €.
Whether this makes sense is debatable. Extraterrestrials probably will not visit the area. Nevertheless, the tourism community is getting a lot of attention through this advertising campaign.
Press article from the regional newspaper Suedwest Presse Ulm, from 27.10.2009