Chances are you have a couple of these in you cupboard right now and they can make great glasses for beers that have high ABV’s and big flavors. The tapered opening condenses the head and channels the aroma right to your nose. The large bowl allows you to warm the beer a bit in your hands and the warming releases more aromatics and flavors. The smaller size (still smaller than a pint glass) is an appropriate serving size for big beers. Probably the least legitimate reason but possibly the most fun is to fill that pretty, pretentious glass with some big, bad, bastardly beer!