People purchase what they know. That goes for consumer goods and professional services. For example in his book, Descartes Error, Antonio Damasio, professor of neuroscience at the University of Southern California, demonstrates that people buy goods that they have an emotional response to. That response is usually the result of having tried it before or having a loved one/trusted friend recommend it. This should not come as a surprise given that our species thrives off of inter-connectedness, so why shouldn’t our buying behaviors reflect that?