Public Relations is a function/division of a marketing plan, marketing strategy, marketing department, etc. This is a fact. It's not arguable. Some companies do elect to use outside agencies for their PR, but it IS a function/divison of marketing.
Any company that chooses to make Public Relations a part of its Marketing Division is not using Public Relations effectively. This is a fact, anybody who has studied Public Relations, anybody who makes any effort to sway public opinion in a positive manner towards a corporate entity more than a product or event, anyone who uses PR as a tool for improving said public opinion in a crisis, knows this.
If a company wants to make it a part of their Marketing strategy, then that is there perogitive. Public Relations should work with Marketing to increase marketing's effectiveness. But it should also work with the executives in the company, it should work with point of sales, it should be incorporated throughout a company in order to ensure that it is able to function properly. Just because some short-sighted business owners don't recognize this, doesn't mean that that isn't what PR is designed for.
Those are your facts, sir.
edit - I figure I'll throw in a few more facts, or defintions of PR from my recently dusted off college textbooks...
"Public Relations is a management function which tabulates public attitudes, defines the policies, procedures and interest of an organization followed by executing a program of action to earn public understanding and acceptance."
(Edward Bernays)
"Public Relations is a set of management, supervisory, and technical functions that foster an organization's ability to strategically listen to, appreciate, and respond to those persons whose mutually beneficial relationships with the organization are necessary if it is to achieve its missions and values."
(Robert Heath)
You said you wanted PR 101, well here it is, free of charge
