The Purple "?" Block, similar to the Original "?" Block, is an idea for a block in Mario. It would act like a normal "?" Block, where when you hit it it will drop something, but differ in the fact that it would only give out power-ups. They would also change depending on locations, such as a Mushroom/Fire Flower in the normal terrain, to things such as Propellor Mushrooms in Mushroom Levels! All in all, it'd be good to have a block that could promise you a power-up of some kind.
Mario has a decent level of uncertainty of whether your life will be saved by that "?" Block, or you'll just get a coin. This idea irons out that uncertainty, meaning that people will be happier knowing where they can go to save their lives.