Is being manipulative bad?

I have this weird talent to manipulate people. It started when I was a kid. I used to talk my way through my parents and get what I want out of them even though it seems unreasonable and irresponsible of my parents. As I grew up, I learned how to observe people, find weakness in them, and use it as leverage to bend them to my will. I keep this facade of looking weak and geeky to make people let their guard down around me. Then when I need my favors, plan A is to simply ask for it for I find that people rarely refuse people they "think" is below them. Plan B would be to assert dominance and use whatever weakness of theirs I have found in my observations as leverage to pressure them into giving in. What do you think? Am I evil?