After recently watching an episode of The Big Bang Theory reminded me of a classic case of forgotten competition, customers make it themselves. The beginning of the episode feature Sheldon folding his clothes with a shirt folder similar to the Flip Fold Shirt Folder available at Nu-Era.

I really like this product because I find folding laundry to be tedious and the end result is never as nice as when you go into the store. But before I spend $19.75 plus shipping to get a plastic one, I might just as easily embark on building my own. Without dimensions, trying this might be difficult but that is not the issue anymore.

While I find the music abnoxious, the plans are there to make your own.  This does not necessarily mean that customers will make their own gizmo that is your invention, but they make something that works to fulfill their need.  To know if this is the case, talk to customers about the problem and find out what their existing solution is.  If it is a homemade version, your job is to provide value beyond their homemade version.  Also remember that the customer may actually enjoy building their own solution, so the value of not having to build it is actually a negative.