It is to the user. Doorstops or boat anchors don’t count.

ozzy payee of electric bills...

Or maybe that the “something “ that didn’t do what you planned may do something else that’s still useful. 

That's why I only order new gear from vendors that have 30 day return policies. It only becomes useless when it can't be returned.

Without looking up the exact quote, I'll paraphrase something else that he said.

"I didn't invent anything. I discovered a lot of things that didn't work."