Ashley states it was used by cotton brokers in New Bedford to tye their cotton samples they took from mill to mill. The packages could be opened and closed at will, and still be secure when left alone at travel. This hitch is really useful for tieing a cow to a pole so it can graze round it. I myself would add an overhand knot at the loose end as a stopper. But I am not a farmer.
Sailors use it to secure a lanyard to a shroud.
The only reason I have included it in the elementary hitches is because its topology places it there. I see no use for it. A keen eye will recognize a capsized Reefknot in it. The Lobster Buoy Hitch is almost as secure as the Buntline Hitch, but more easy to untie. It is used to tie timber.