Designers know there's a market for Facebook apps that allow you to see who views your profile. And they also know that Facebook has strict privacy rules forbidding it. So many designers toe this line, bringing you right up to the edge of something resembling actual knowledge.
Typing the word "statistics" into the Facebook app directory returns a long list of traffic tracking apps, similar to Facebook Insights. Most of them aren't as good. But you'll find a rotating and ever-increasing list of gems that do things like mine your status updates for the words you use most. Just be sure to keep one important point in mind: These apps mine your profile for interaction. When someone "likes" a photo you post, comments on your status update or otherwise interacts with your profile, these apps know, and they may be able to build models of your most active friends. But if an ex-boyfriend is simply lurking around your profile, there's absolutely no way to tell, so don't believe the apps that tell you otherwise.
Be assured that app designers are constantly prodding Facebook for workarounds that take you past the Facebook privacy rules, and every once in a while, a designer finds an inroad. Generally, when this happens, an app that actually does return interesting information about your profile views has a ticking lifespan, which ends when Facebook finds out and shuts it down. For example, take Breakup Notifier, which claimed, "You like someone. They're in a relationship. Be the first to know when they're out of it." The app worked by mining your friends' relationship statuses.
In 36 hours, it attracted 700,000 visits and more than 3.6 million users [sources: Heussner, Tsotsis]. And then, poof, it was gone within the week, squashed like a grape under the stiletto heel of Facebook, which blocked the app.
If you keep your eyes peeled, you might come across the next banned app before it's banned. Until then, learn to live with the fact that -- definitively, finally and with an exclamation point -- you can't see who's stalking you on Facebook, and that's the final word from straight from the Zuckerberg team.