This afternoon on Techcrunch, there's a nice post from guest author Shelby Bonnie, the CEO of Whiskey Media. The post, Let's Kill the CPM, goes into why we should reform the traditional method for measuring many aspects of advertising, Cost per Impression.
While I find the post to be an interesting read and I agree with the weaknesses of CPM-based advertising strategies, I think that the real answer to advertising strategy requires a much more thought-out approach than simply hanging ads on a site. Unfortunately, that's the way that many organizations approach their marketing, and it's so closely modeled to traditional advertising that the practice requires little justification within the traditional business structure.
The ugly truth is that One-Size-Fits-All is a poor formula for any advertising strategy. While I'm a big fan of CPC advertising and Adwords, I also know that as a blog operator, while running Adwords is convenient and easy, the idea that anyone will be driven here by my content and then click through one of the Adwords ads is almost funny. Meanwhile, over on the SV Fashionistas blog that JJSakura has put together, some of the affiliate banners are actually producing click-throughs and purchases. As noted in Kill the CPM post: "All Impressions Are Not Created Equally".
Anyway, it's worth a read.