Not all comics need to be elaborate 30+ pages. In fact, comics aren't even necessarily in well defined panels and may not contain any words. To use Will Eisner's nomenclature, comics are Sequential Art.

Ponoko's Photomake illustrates this brilliantly with the simplest comic possible:

Photomake lets you draw anything by hand, take a photo of it and turn those drawings into real life objects. They have a video next to the comic that explains the process in more detail but this little comic is so short and to the point that its simplicity also implies the product's own simplicity. It's as though they're saying, "No, really, it's that easy. Take a photo, and the next you know, your sketch is now real!"