Poor planning on the Mint's part IMO. After the coin is struck, they run the coins through a edge-lettering machine, which pushes into the coin. This makes the metal on some of the coins stretch outwards, producing the 'waffle' effect that you see here.
I don't think that these will ever be worth anything, they are so common. If anything, the coins without this will be worth more as they are more appealing without the flaws. Unlike some error coins, these are too common to ever fetch a premium IMHO.
Edited by noahs-numismatics
11/03/2013 2:56 pm