This concept, that originated in the world of financial investment, holds true in business too. Applying it isn't easy, however, because it requires business managers to know when an idea is actually true, despite 'common wisdom' suggesting it isn't. One way of doing this is to pay proper attention to empirical evidence (something marketers are not famous for). This LinkedIn post by Peter Weinberg refers to a few areas of marketing in which common practice is at odds with scientific data.

The Smart Marketing Book is one of the few marketing books available that is well grounded in evidence rather than opinion.