Just curious here. Why do different grinds exist? I read somewhere that the finer grinds give a bigger nicotine hit because of the particle size. Makes me wonder why the American snuffs are the fine grind scotch variety, while European snuffs have many different grinds. German snuffs are mostly coarse and the Indian snuffs are fine?

Because they have different nose feel and absorb flavoring differently and people have different preferences.

What Snuffbox said. Different grinds work with different flavours in different ways, and have to be snuffed in different ways. The vast amount of variety that this allows for, is for me, one of snuffs greatest appeals.