I had too much fun matching an image to this post.
From the Budapest Marzipan Museum, marzipan
Teenage Mutant Ninja Turtles.
I've discovered via Project Wonderful that it isn't only advertising that's networking -- it's the act of advertising as well.
Promoting a web comic requires cobbling together a portfolio of sites that will host your ads. Many are quite small, with 50 - 500 visitors/day, so you visit a lot of sites as you shop. That's how I've discovered comics that eluded my radar, some comics blogs, a networking site for woman cartoonists and various oddities.
So far, I only host ads on one of my sites -- this one -- but presumably people are discovering my work as they shop for ad space. The more adventurous might tap into my network of sites.
The "button" size advertisement is the business card of web comics. There's a lot of ingenuity involved in packing an ad message into a space so small, giving the better ones an attraction not unlike marzipan, or sushi. It's almost an art form.