Quest type: kiting
Purpose 1: bring mobs from one place to another
Purpose 2: Escape from a horde angry mobs

It could be used for ambush quests where you have to escape, or quest where YOU ambush the mobs and have to bring them to NPC for the main attack (tactics!).
You know, stuff like that.

Mainly a good survival exercise and running fun with a train of mob on your heels. Sweet.