"As modern economies move further into information-based systems of capital, intellectual assets such as patents, industrial designs, copyrights and trademarks continue to represent a large portion of society's wealth. Indeed, a majority of the book value in many corporations and other business entities is now represented by "goodwill" and other forms of intangible wealth, much of which commonly resides in a portfolio of patents, designs, know-how and other legal rights. It is also common for businesses and individuals to transfer intellectual assets between each other in the form of licenses, assignments of rights, and the like."

http://www.faqs.org/patents/app/20090037342