Eric von Hippel, at MIT’s Sloan School of Management, was interviewed by Deloitte Review on the subject of open source technologies in the field of innovation, he makes a very nice mention about Arduino:
Open hardware is a set of open platforms and tools to support people who want to design their own hardware. For example, the Arduino board is a basic electronics processing board with open specifications that anyone can copy and use in their own projects. People are proving that profitable firms can be set up around supplying hardware built to open specs.
It seems to be a really good article, you can read the whole thing here.