Most players think of hunters as a burst damage pve class. While hunters can do a lot of damage very quickly, especially with lucky critical hits, they also have the option of building around dots.

With the recent change to trap mechanics, hunters have the ability to drop traps in combat. This means that in every fight, hunters can add immolation trap bonus damage to their dps. When hunters spec for improved trap combined with improved serpent sting and the obvious damage over time abilities of their pets, hunters can build a rather formidable series of ticks much like a warlock or shadow priest.

It's not a common build, but it is a different fighting style, and it presents a number of problems for opponents, especially those who might have trouble dealing with multiple damage over time sources. Hunters have melee, fire and poison dots, which means even players with certain immunities or defenses will have trouble avoiding all sources of damage.