Arduino is used by many professionals. It is cheap enough that you can buy it on your corporate cards and you boss won't ask many questions. As such many products start with an Ardunio based demo, and if/when the demo is a success it moves to a real company project with a real budget.

The question though is does this add value for the owners of Arduino? All too often when a project moves from the demo to real engineering (making a demo something you can sell is typically about ten times harder than the demo) you select all new hardware.