It is one of the weapons that deals great damage needs great precision much like the Sniper family. The arrow has a small delay before being shot due to the bow having to be pulled back. While the initial hit deals massive damage it also deals some lingering damage the same way as the Flame and Napalm family works. It is also distance-based much like the sniper is. Due to the fact that it shoots later than most weapons it is advised to be cautious about terrain effects on the target since the first weapons to land may affect the arrow's landing spot.
Whats the point of keeping the bow after you ran out of ammo? How about throwing it as well to deal more extra damage! Just like the arrow, the bow is also distance based ranging from 4 to 10 damage. It has also a bigger radius than the arrow so the bow can still deal damage even if your arrow missed the target slightly.
The final tier shoots only the arrow and not the bow, but increases linger damage from 2 to 5 due to the flaming tip of the arrow. There is no change to the arrow itself, but the increased linger damage is not affected by distance making it deadly even in close range.
The linger damage has a slight AOE while the arrow itself does not, so it is possible to hit for the linger damage, but not get the damage from the arrow itself.