Here is a sign in a shop selling film CDs:In Britain or the USA, pieces would be omitted, because CD is a count noun. But use of pieces for countable things seems to be the norm in this part of the world.
Here is a sign in a supermarket:Again, we find pieces used to refer to something countable, apples.
I strongly suspect that this usage will become the norm in World Englishes. After all, it is perfectly clear, so everyone can understand it with no problem.