One is the organic search through search engines and the other is the inorganic or paid advertising methods.
The inorganic advertisement is not for most people as it costs you a bundle without any promise of profits.
Article directories provides the organic is free and tough.
The competition is very fierce for most targeted niche markets.
How ever that is the only way for people without a big spending budget for ads.
If you study most of the search engine systems you will find they are looking for satisfying the customers.
The customers are looking for information about something of value to them.
The most relevant website that provides that content is a winner.
There are other factors they consider like linking from other external sites, yet without article directories content you will get no where.
When you start writing articles about certain topics you should focus on information that is easy, clear and practical for people to use.
We all come to know about something through exchange of information.
Friends and relatives inform us about various things in a day.
We keep all this in our mind sand use some of them when needed.
The same way we also read in papers and magazines certain information.
We gather many valuable pieces of information form time to time from various sources like Article directories.
That is how this information gathering works.
The same way your article is going to be one of the sources for most people.
Whether it is useful to them or not depends on how valuable a price of information you are offering for free.
If you information is valuable then people start to make a note of you and read more from your source.
They will also tell others about it.
Article writing creates free content for your own web pages.
You must submit these articles between 400 -1000 words to as many article directories as possible.
This kind of syndication helps you to spread your information around.
Many magazines and other publishers are always looking for information and they will pick up your article if it has valuable information and syndicate it.
In this process your website is mentioned in many other sites.
You get external links without you trying for them.
The more articles you write and submit them to Article directories consistently the more publicity you get and that is how the search engines will notice you for content and valuable links.
In a matter of time you have a very good chance of getting to the first or second page for your niche with the right keywords.