It definitely works. I'd caution against over-doing it though. It's not too hard for the engines to ID sites for which the majority of their backlinks are blog posts and comment spam. Keep it real, honest, relevant, contributory (not just fluffy me too posts), and as a part of a total backlink proflie there should be no issues.

I'll also add that if you're only waking up to this approach (your words), it suggests to me you could benefit from spending more time: Reviewing log files, reviewing competitors' backlink profiles and Web sites, and doing more keyword research. When doing all of that, not only does one notice what you've noticed, but a whole slew of other interesting information reveals itself along the way, often including new ideas for content and marketing your site.

You are definitely NOT a caveman! Thanks!...KF