For most of us, perhaps business aside and irrespective of the follow link, we're often satisfied if someone recommends our content with a friendly nod, particularly if their use of our content is not overtly selfish. Hey, for that matter, we may be downright flattered to get any attention at all. (In which case, like I mooted, read everything on SEO!)
Then again, as our sites begin to grow, our content will gain attraction and, while some will be welcome and the recyclers duly thanked, and while some will be unwelcome and the recyclers duly sued, most attention meets a middle ground. This is where a more pragmatic approach comes in. Rather than spending time chasing tails, for many of us, we do better to ask ourselves how can we create a benefit? Remember that in most cases even unsolicited use can help to boost traffic. This depends on what's being reused, where it's being reused and how, if at all, it's being re-mastered. This also depends...