These links may have a keyword rich anchor and are DoFollow (most of the time). Each domain that you are promoting should have about 40+ articles (if you're trying to get the highest serp possible. 40 articles is a lot of writing no matter how ya swing it, but I've found that reviewing a product is probably the easiest way to go.

Traffic from Article Marketing
Imagine that you write an article and it gets submitted to 500 article directories (some with high PR and link juice). Those 500 sites now link to you with a very relevant keyword anchor. This brings you valuable free traffic in two ways:

1. The more backlinks you have, the higher your site will position on the search engines (serps).
2. A quality article brings you "the author" visits to your blog from the links included in the about the author section.

Submitting Articles the Easy Way
If you're serious about Article Marketing you'll want to have your articles submitted automatically to article directories for you (time is money). I've used three services for this.

The first (and best) would be Article Marketer. Article Marketer is a subscription based service (it costs $50.00 / Quarter or $160 per year) for unlimited article submissions to 5000 + article directories. Article Marketer reviews your article in 1-2 days (other services can take up to 15 days) and informs you of any potential issues with your article before distribution begins. Article Marketer will not distribute your article until it meets certain criteria. Article Marketer provides you with distribution and exposure reports as well, which are really nice because you want to see what you're paying for frankly.

The second one is called iSnare. iSnare.com will register you at about 500 directories and automatically submit your article to them automatically for 2 dollars per article. iSnare takes about 5 days to review your article and is not as thorough as Article Marketer. As long as your article has 400 words they'll push it out. That may sound good, but it isn't. Article Directories are fraught with many rules and it's really important that your article be universally acceptable for maximum exposure.

Finally, the third Article Submission tool is DigiXMAS Article Submitter. This is a free article submission tool that submits your article to hundreds of low pr/ranking article directories. DigiXmass Article Submitter is a semi-automatic process and requires several manual steps, but it is a free solution.

Is Article Marketing Worth it?
You bet it is! Nothing is better than getting 1 way backlinks to your site with relevant link anchors. These one way text links can rocket your site towards the top of the SERPS, especially if your topic or niche is under one million results.