Are blogs bigger than plain Web pages?

This may seem like a no-brainer question, after all, most Weblogs are set up to display 5 to 10 new posts on the home page while a plain Web home page might only have 2 or 3 short articles and information. But WebsiteOptimization.com did a study to find out if this is true. What's interesting to me was that the more popular a blog was, the larger it's home page was. This is, I'm sure, partly due to the fact that less popular bloggers often don't write as much in their blog posts. But it seems that advertising is more popular as well for the more popular blogs, and that increases the page size.