Tapping Mobs (Alliance leveling guide)
Tapping is to hit a monster once or twice. Basically, this is used in reference to a low level character ‘tapping’ a high level monster and then having a high level character kill it. In previous builds of WoW, the first player to ‘tap’ the monster would get the experience points. This has been changed and now it is % based on the amount of damage you inflict.
there goes all the easy exp xP