1. Post inflamatory comment about someone egotistical enough to have their own "blog", and include link to their "blog".
2. Since they are egotistical, they will be checking their preferred blog indexing and serching services for links to and mentions of themself.
3. They will link back to the post of yours that mentioned them with probability 0 < p < 1
4. ?
5. Profit!

And I am ashamed that I've had so much exposure to the circle-jerk-osphere that this idea would even occur to me in the first place.