Public relations is up to 10 times more effective than advertising due to the role of gatekeepers. Gatekeepers provide an independent voice about the merit of your company and whether or not your press release/ bylined article is newsworthy.
Advertising access is based almost solely on the role of money. Meet a few rules about common decency, and you can achieve almost any size ad you want, in any publication, and in any format. People are jaded with promotional schemes and almost entirely turn off from your message unless you find some innovative way to approach them. And just about every approach has already been tried.
On the other hand, the neutral opinion of editors serves as a screening mechanism to determine whether your press release gets covered, on what page, and in what manner. Publication of bylined articles are also monitored by similar gatekeepers who must determine whether your article provides useful information to the general public, or in the case of trade magazines, the general readership.
The concept of gatekeepers has proven so beneficial to public relations, it is being applied by Google as well for search engine optimization. SEO uses inbound links to determine the merit of your website, but SEO professionals have tried to foster these links in a manipulative manner. Now, however, the Google ranking algorithm is being adjusted to only count those links granted by someone else. In this manner, they can determine whether people are linking to valuable, original content in an unforced manner.