I'm running blogs quite successfully on Adwords, there is just something very obvious that MANY of you haven't seem to grasp. Based on the keyword you're targeting, Google has a basic requirement of how YOUR landing pages should be formatted. If you're bidding on buy keywords, like "cheap weight loss pills", and targeting it with a blog, then you will be slapped or your QS will go down. For that keyword, you need to run a page that actually sells something, sells a diet product; not provides the visitor with some life story.
On the other hand, if you're bidding on "how to lose weight" or " losing wieight fast"; then a blog landing page WILL last longer. Since that keyword can pertain to informational landing pages, which Google will be fine with.
So you really need to understand what type of keywords you're targeting, and get creative.