ok, say you have been killing a player of the opposite faction 3-4 levels lower than you because you want to finish the quest your on which requires you to kill the mobs that player was killing
so, you've been killing him every time he spawns just to keep him out of your way until he calls his level 70 friend down who just sits by your corpse and doesn't seem to leave after 4-5 kills
pst someone in the area to join your party and come down and kill the mobs, even though your in ghost you get the kills