“The proportion of a company’s total market value that exceeds its book value has increased from 40% in the early 1980′s to over 80% at the end of the 1990′s. This means that only 20% of a companies value is reflected in the accounting system… [thus the largest portion of a company's economic activities] can easily be overlooked.”

Jurgen H. Daum in his book Intangible Assets and Value Creation