PR and advertising often go hand in hand but they are two completely different things with a completely different goal and overall effect. While advertising is exclusively focused on promotion of products or services with an aim to encourage target audience to buy, PR is specialized in communication with the public and media.
Just like advertising, PR often helps increase the sales as well and may include elements of marketing. However, it is mainly focused in creating positive publicity about a particular company, organization or individual and maintains a good reputation in the public. By doing so, PR helps create a relationship between let’s say a commercial company and its customers who are more likely to choose the products from a company they have a good opinion over those from a firm they have never heard off before or heard something negative about it.
The public reacts very differently to an add than to a newspapers article or a TV report. They know very well when they are reading/looking an add and the information they are communicated is perceived with a certain degree of skepticism. They know that the add wants to persuade them to buy a particular product or service and will either believe or disbelieve the information they are communicated. But when they are communicated news about a new product or service through a third party, for example a newspapers or online article they perceive it as informative and worthy of their attention. A press release for instance does not directly encourage them to buy but it often achieves just that by creating a positive image about the product/service or its manufacturer, or both.
Either a professionally led marketing or PR campaign is inexpensive. The cost depends greatly on who you hire but generally, PR is a lot less expensive than advertising. But it is also true that PR has a lot less control over the way their clients are presented by the media in comparison to paid ads that oblige the media to publish them unchanged. At the same time, a press release is published only once by a single media, while the adds can be published over and over again. But given that press releases and other PR tools to attract publicity usually achieve a greater impact on the target audience, there is no need for repetition of the same stories over and over again to attract attention of the public like this is usually the case with ads. In addition, an article or TV cover of purely informative nature is more likely to led the target audience believe the content of the adds. As a result, PR campaigns often proceed or/and accompany marketing campaigns or are an integral part of advertising strategy.