Used for adding the most physiologically extreme emphasis to a sentence. It is many times more intense than an exclamation point. By adding this at the end of a sentence you are implying that you are exclaiming so intensely that you have destroyed your vocal chords. Two or more of these at the end of a sentence is unnecessary as that would mean you have destroyed two or more sets of vocal chords which is not possible.
by defried January 21, 2012
by defried July 10, 2011