Well, you put duct tape on your butt and try to find other people that have duct tape on their hind quarters to meet them. Even if you don't find other people, it is an excellent conversation starter.
We just decided to use duct tape. Other tape might fall off, but duct tape is awesome and doesn't fall off. And it was unique. Who else would wear duct tape to a concert?
It originally started as just a few Yahoo! Clubs (RadioU & GodsKids of Ohio). They did it to meet eachother. Quite a few of them did meet eachother. Anyone can do it at a Skillet concert. They just have to get other people to do it if they wanna meet other Skillet fans who like duct tape. Or they could use it to meet new people.