What good are they for? How do you know the good quality from poor quality? It's as simple as they all follow simple demands for their quality.
When you read many seem absurd, they contain spelling, or stylistic mistakes and typos. This is due to the speed at which they are written. But good PR articles will avoid this. If you find articles just too full of keywords, they are spelled correctly and the browser will appreciate them. Therefore, pay attention to automatically generated PR articles, so many of them are going through and nobody knows anything, but the quality of the search engines is increasing.
Quality is important
This is primarily about originality and a variety of words. Pr articles must contain many other words so that they are not considered an information ballast.