"Sweet potatoes are a popular snack in Taiwan. Not only are they are grown here, but because they are in the shape of the island itself."
I've read something like this before. At first I thought it might actually be true, as near my first apartment was always a small vender like the one above selling yams (oh yes they are actually yams and not sweet potatoes). However even though I may have passed that tiny vendor a thousand times, i never once saw anybody buy one. In all my years here this picture above was the first time I saw somebody buy one.
I must also say that a few weeks ago a friend bought one. i didn't actually witness this, but i did see her eat it. She was not happy, and i had a piece for myself and it was like eating chalk. So if that is indicative of how all Taiwanese yams, i understand why it took me over nine years to see somebody buy one.