Trust and Zeal in Open Source Advocacy
http://www.linuxdevcenter.com/pub/a/linux/2005/04/21/advocacy.html

Bacon, Jono
O'Reilly and Associates
2005

Abstract:

People who are unfamiliar with open source generally don't like evangelists--at all. This is particularly true for managers who may take the same disdain to evangelists that they take to salespeople and marketers.