1. If there is a "Comment" section, the author is always checking it
2. Analytics and page view statistics are boring to read
3. Comments (0) just looks depressing
4. Blog posts always take more time than they seem to have taken
5. How could you pass up a chance to be anonymous and brutally honest
6. Your few words may be the ones to inspire the next 10 posts.
7. Reward a blog for not containing Ads and Banners by commenting
8. Commenting builds community and encourages the spread of good content
9. Commenting is a public business card if you include your url
10. Comment onto others as you would have them comment onto you.
Lets spread the love and comment on everything.
While we're on the subject... There is a site that actually tracks all of your comments. Check it out: BackType.com
They don't catch them all, but you can submit blogs to their crawler.
Here is my page: http://backtype.com/austincurtis