Once you understand and accept how Friends works it totally makes sense. It's basically a "Fast Talk" con that confuses your target in such a way that the con is forgotten as long as you are no longer around when the spell wears off. It's useful to quickly get past someone or get a better deal but only if you can get away before the spell fades and the target realizes what just happened and confronts you. It's not useful and obviously detrimental if you stick around so either don't use it in situations where you can't quickly GTFO of there or face the consequences.
