chadz replied to a post and said that it was based off the enemies armor (I just assumed he meant enemies you kill or die near you). I noticed I got more xp when I was killing people, I'm assuming you get some if you're near enemies who die, and more when you kill them. And the xp that you get is determined by how expensive the armor was on the person who died.
Also, I don't think you get an XP tick every time someone dies near you, I think it adds up and every few mins you get the xp.
Also, there's a post with 3 pages about 5 topics down in the list if you were to have browsed through you'd see the almost identical title.
