Read the Innovator's dilemma to understand that when a new product is launched nobody really knows what is useful for.

It happened to the Iphone, it took at least a year and a half(it had no apps at launch!!) to start being useful for something and it happened to the Ipad: people did stare at it and say "it's cool, but I don't know what I could use this for", There is a video of a news reported asking this to people about the Ipad.

Selling millions of devices is the best feedback they could have. People always find crazy uses for any new tech.