It really depends on the person for me. For most, I use people that consider me a friend to be entertained, to have power and control over them. Friendships appease my boredom and I can feign empathy and other emotions fantastically well that no one is the wiser unless they're very smart. I've been found out before, and I hated being caught so I just cut my losses and moved on. However, I have run into sociopaths, psychopaths, and narcissists that have a different dynamic... I am friends with a psychopath for example, and I enjoy our intellectual discussions and also how this man challenges me. I find the thrill of playing mind games with another psychopath to be quite a lot of fun. I see interpersonal relations as a game, that is the honest truth... But I do tend to respect people and play with them less if they recognize me for who and what I am and don't shrink back in fear or just write me off as "evil".