There are a few great blogs focused on advertising on the web which you might check out if you do not already read them:
Adverblog is smart worldwide advertising commentary from a UK-based account planner. Adrants is the People Magazine of the advertising world, offering witty commentary from a veteran ad guy. Ad Jab is group analysis from the agency viewpoint and Seth Godin offers a thoughtful, quirky take on the world that is marketing. B.L. Ochman’s What’s Next Blog is not limited to marketing per se, but gives you a good tap on the pulse of the blogging world from someone who comes from a marketing and PR background.