You know, I've generally assumed that t-shirts bearing the characters and logos of webcomics did little more than provide some financial support to the creator. I might buy a shirt so that I'm sending $20 to someone whose work I appreciate.
But today I was in the pet store wearing my Abominable Charles Christopher shirt. The checkout guy says that it looks really cool and asks what it's from. I tell him it's a webcomic called Abominable Charles Christopher at which point he runs some blank receipt paper through the register, tears it off and makes me repeat the name so he can write it down. He thanks me as I start to leave.
I stopped a bit at a display near the exit and was looking over some material there when the guy rushes over to me with his iPhone out. "Is this it?" he asks pointing to the screen on which he had called the site up.
So I guess t-shirt marketing works after all!