Although there are many copycats now, EzineArticles (EZA) was the original article directory and they still have more articles in their database than any other article directory on the internet. Their database contains articles on every subject imaginable. The articles are organized by main categories and then further organized by nested subcategories. Each article is assigned to only one specific subcategory.
Anyone can sign up to submit articles to EzineArticles but before submitted articles are placed in the EZA database, they must be reviewed and accepted by an EZA editor. Certain rules must be followed and there can't be too many grammatical errors. However, the actual factual information is never checked so there are many articles in the EZA database that contain factual mistakes and the overall quality varies a great deal.
The writer is not paid for the articles but he or she is allowed to place a blurb about themselves and/or their website/business with up to two links at the bottom of the article. This is called the resource box, although it doesn't actually show up as a box.
Anyone can reprint any articles from the EZA database for free with the agreement that they cannot change the article and they must include the resource box with the links. Many webmasters and newsletter publishers use these articles. However, there are some serious drawbacks to doing so. Since the articles can be freely used by anyone, they end up being published on many sites, sometimes numbering in the hundreds or even thousands. Therefore, they are almost guaranteed to be duplicate content that will likely have been seen elsewhere by the reader.
Unfortunately for writers, many publishers leave out the resource box or don't make the links active so the one main advantage to taking the time to write the articles and submit them to EzineArticles goes out the window. In fact, the resource box is left out the vast majority of the time. EzineArticles does nothing to discourage this practice even though it is officially against the rules. It is near impossible to stop this if you are a writer.
Several years ago and for a long time, EzineArticles enjoyed a special place in Google's heart. Article pages within the EZA database had a tendency to rank very high in Google's search results, often appearing in the top ten within a few days of being placed in teh EZA database (the good 'ol days when internet marketing was simple). Furthermore, a link from any page on EzineArticles would give a significant bump in link popularity, more than with most other sites. This would in turn increase your search engine rankings for your own website pages in a hurry.
This inspired a great number of webmasters to write dozens, hundreds, even thousands of articles for the EzineArticles database. During this time, this would generate search engine traffic both by increasing search engine rankings and by people clicking on the links in the resource box when the articles ranked high in Google. However, this heyday of EzineArticles is long gone.
Starting with Google's Panda update, a major over-haul of it's algorithm to demote pages/sites with low quality content, EZA pages in the Google rankings plummeted almost overnight. The situation has not improved since then, and in some ways, EzineArticles is a ghost of its former self.
EzineArticles makes most of its money with Adsense ads. Therefore, almost every page of their site is loaded with Adsense ads. They seem to always be tinkering with Adsense ad placement and sometimes their pages are so overloaded with ads, it's hard to find the actual content. In fact, they have a special arrangement with Google so they can legally deliver more Adsense ad units than most webmasters are allowed to have on each page of their site. Their ads have gotten worse since the Panda update because they're trying to make up for the revenue they lost.