Link building is done for two reasons. One, to get direct traffic from the links. And two, to get better rankings from the search engines. Now what has link building got to do with search engines? You see, the search engines count links as "votes". The more one way back links you have to your website, the more "votes" you have. Search engines see these sites as authority sites, and any content that you post on these sites will rank well.

Once you understand this, you know where article directories are getting all that traffic - from the search engines! There are hundreds of article directories online. Some are already well established and any articles that are published on these sites will start to show up in the search engines in a matter of days. So if these are your articles, you are already getting exposure for your business. The readers will read what you have to say in the articles, and decide whether or not they want to visit your websites.

Each article contains two to three links in the author resource box. The author resource box is where you promote yourself or your business. That is how online visitors find your websites - by searching for the information they want, reading your articles, and eventually clicking on these links to visit your website. Once they are on your website, you got yourself a potential customer. Of course, the search engines also recognize these links and your websites will start to show up in the search engines as well.

Social bookmarking works in a similar fashion, except that you don't post articles. You post URLs to social bookmarking websites. Social bookmarking websites are community based. That means if one member of the community finds a great website, he or she will be able to share it with family and friends through the website.

In other words, once a link has been posted on a social bookmarking site, others will have access to the links immediately. Search engines will also be able to crawl these links and visit your sites more often. In addition, social bookmarking links also count as back links for your websites.

The nature of social bookmarking sites is similar to the nature of the Internet - it is viral. That means for sites that are worth mentioning, the links will spread very quickly through the social bookmarking community. One person will share the link with two, two will share with four, and so on. The viral effect has taken off. Note that while the viral effect continues to work, the business owner is not spending any money on advertising. That's why more and more business owners are looking to promote their websites using social bookmarks.

Remember, on the Internet, it's all about traffic. And traffic depends on back links. The more back links you have, the more traffic you get. So if you haven't given article submission or social bookmarking a try, it's about time you do.