Most executives have a general idea about what public relations is; they know they need it, but don't know where to start.

When asked, people often define public relations by some of its more visible tactics - coverage in a newspaper, pictures of products in magazines, television interviews etc. What they miss is the celebrity outreach, employee communications, crisis communications, writing, relationship management, trade show support, event management... public relations is all this and more.

A close colleague once explained public relations thusly: "My job as the public relations person is to help raise [consumer] awareness about the company through a variety of different means, in an effort to assist sales and therefore moving more product."

Another, more academic definition states:

Public relations is the management of communication between an organization and its publics [your audience or target market]. It is the deliberate, planned and sustained effort to establish and maintain communication and mutual understanding between an organization and its publics.

For most companies, the main reason for embarking on a public relations campaign is to obtain media coverage, which in turn can generate sales. The more exposure your products get and the more compelling the call to action (your "come and buy this cool new thing!" phrase), the more sales you will see.

There are several specific "ground rules" about public relations:

Public relations is not marketing.
Public relations is distinct from marketing in several ways, although their boundaries often overlap because they both deal with a company's relationships and employ similar communication tools to reach the public. Marketing encompasses everything that you do to sell your product, from packaging to your point of sale materials. Public relations includes everything that you do to talk about your product's benefits and features to your customers.

Public relations is not advertising.
Advertising is paid space or broadcast time to promote a product. Public relations is more cost-effective (Proctor & Gamble did a study in 2006 and concluded that their return on investment was better from a public relations campaign than they get from their 4 billion dollar advertising budget) and can reach a wider audience than advertising. Consumers are inundated with ads - it's everywhere they look. It's no surprise that they've begun to just ignore it all. Surveys show that editorial coverage, typically generated by public relations, is five to seven times more effective than advertising.

Public relations is not guaranteed.
There's an industry joke that says the only guaranteed public relations tactic is advertising. Public relations is a process, a series of actions, changes or functions that bring about a result. These actions usually involve another person - namely an editor, reporter or producer. The job of the public relations person is to write convincingly, speak eloquently (and often, directly) and convince the editor to cover their client. Sometimes, it goes well and results in coverage, and sometimes, it doesn't work at all. It all depends on timing, relationships, contacts and sometimes, even how a reporter is feeling that day.

According to a recent Economist article,spending on Public relations in America has been growing strongly  and reached some $3.7 billion in 2005. The forecast is that public relations spending will grow by almost 9% a year. This is faster than the overall market for advertising and marketing, now worth a colossal $475 billion and growing at 6.7% a year.