If you're selling life insurance, placing ads on a popular webcomic Web site that appeals to college kids is probably not going to be as effective as a more sedate, establishment Web site.
EXTRALIFE is a multi-panel webcomic by Scott Johnson that can sometimes feature ongoing narratives over the course of several weeks.
That said, if you want a great video game comic on a very regular basis, the webcomic community is a fantastic place to look.
START! releases a new webcomic every week with topics ranging from Pokemon to Superman, Raving Rabbids to Xbox Avatars.
The most recent of these exchanges involves the creators of the popular webcomic Penny Arcade.
If you're selling something a bit outre, go for the webcomic.