Well, for them to پرستار me first. :P I always add back.
But when it comes to me fanning first, I'd add someone if they're a پرستار of what I'm currently obsessed with, and if we have a lot of common interests.
Well, if people پرستار me, I'll پرستار them back because it's the nice thing to do. And for me to پرستار someone, I choose people with good personalities and things in common with me.