We all want to see who is looking at our Facebook profile - after all, wouldn't it be neat to see who is "Facebook stalking" you? At the same time, I think its safe to say that no one ever wants the world - or anyone else, for that matter - to be able to see whose profiles they have been checking out. Every one of us is "guilty" of looking at someone's Facebook profile that they probably shouldn't have (exes, that girl in high school that you totally had a crush on, etc).
There are also plenty of apps out there that claim to be allow you to see who had viewed your Facebook profile. Wow! That's awesome! All you have to do is click on a few buttons, like an App or two, and WHAM, you can see who has viewed your profile. Great!
Yeah, it's totally a lie. According to Facebook themselves, you cannot see who has viewed your profile. No app can allow you to do that - not now, not ever. There is no way anyone can ever see whose profiles you have viewed, and you can never see who has viewed your profile.
So, what are those links? Spam or viruses. Approving an App likely gives the App creator access to information that you probably didn't want to give away to them - contact information, your friend list, etc.
Make your life easier - don't click on these links!
That being said, some social networks are different. On LinkedIn, for example, you can see who has looked for your profile - just go to your profile, scroll down and look at the "Who's viewed your profile" sidebar.