Mythmaker1 on 12 August 2013
It's really not that uncommon for this sort of thing to happen. Especially for games in a series.
As to what caused it, I'm going to say Kirby's Dream Collection, the seriously low price, and the announcement of Yarn Yoshi helped spur sales.
I believe in honesty, civility, generosity, practicality, and impartiality.
