Article marketing services are used to generate backlinks to websites, causing them to rank higher in the search engines for their chosen keywords. Users submit articles that are in turn submitted to many other websites. These websites link back to the user's website, creating the impression that his is a real authority on the subject.

Article marketing services understand that search engines look for relevancy when calculating rank on their results page. They know that relevancy is in large part determined by the number of backlinks citing a certain website. As Google's founder put it, it's like when an academic paper is cited by others. A student himself at the time, he realized that relevancy online can function in the same manner reputation does in academia.

Article marketing services were born soon thereafter to take advantage of this insight. Of course, Google has since gone on to be much more sophisticated in how they compute relevancy, making them the one search engine most resistant to gaming, but the heart of their algorithms is still informed by such notions. Thus, it is possible to set up your own network of websites that link back to a site you'd like to promote, creating an authoritative impression.

This is what article marketing services do. Your article appears on all the sites that make up their network. So suppose you sell widgets. You write an article on widgets, containing backlinks to your site associating your keyword, "widgets," with your site "widgets.com." Now using an article marketing service, your article on widgets gets published by all the sites in the network. This creates the impression, to search engines, that your article is being cited by all these different places - surely you must be an authority on the matter!

Of course, just as it doesn't help to be cited by a no-name publisher in academia, neither does it help to have just any ol' website host your article. And thus, when choosing an article marketing service it's important to use one that has a network of powerful sites, websites already well-regarded by the search engines. After all, who would you trust to learn more about widgets from, a website that just came online a week ago or a website that has been around for years?

And not only that, of course, but a website that may itself be cited by other well-regarded sites ("cited" as per the number of quality backlinks it itself bears), or a website that is devoted exclusively to widgets and covers nothing else, or a website that...you get the idea.

It's about trust.

So when choosing an article marketing service to use, it's important that the company actually maintains not just a network, but a quality network, one that will provide your site with quality backlinks which cause search engines to regard your site with favor.