Greg Meyers analyzes the differences and similarities between advertising on TV and PPC search advertising. Similarities include day parting strategies and call to actions. Differences include viewer intent.
Meyers also points to what PPC marketers can learn from TV advertising. Aside from his own rant, he mentions three other blogs, such as SEOmoz.org, Search Engine Watch, and ANA Marketing Maestros, which have posts on the same topic.