Wired has a great interactive info-graphic on the path blog posts take once you hit the "go" button.
You have a blog. You compose a new post. You click Publish and lean back to admire your work. Imperceptibly and all but instantaneously, your post slips into a vast and recursive network of software agents, where it is crawled, indexed, mined, scraped, republished, and propagated throughout the Web. Within minutes, if you've written about a timely and noteworthy topic, a small army of bots will get the word out to anyone remotely interested, from fellow bloggers to corporate marketers.
Since I joined the CNet blog network I've found that more and more of the content I post is scraped and put on link harvesting blogs. There appear to be a few keywords (Microsoft, Apple, MacBook) that drive the most leeches.