I just wanted to mention one thing that I know many of us simply over look. When it comes to backlinks and SEO, only one link from a unique domain matters.
Article submission to article directories is a great way to build backlinks and drive some traffic to your blog. I have noticed a lot of people submit many articles to the same article directories with the same anchor text links either in the body or in the resource box. If you are doing article marketing for backlinks, you need to keep in ind that only the first backlink from a domain is counted as backlinks. For example, if you submit 10 articles to ezine all with the same backlink like (my keyword), only the first link matters when search engines rank you for the keyword "my keyword". The rest doesn't do you any good.
So, what should you do?
1- Instead of wasting time submitting to the same article directories, find more directories and submit 1 or 2 articles to more article directories, thus getting more backlinks from unique domains, which actually matters when it comes to seo.
2- If you still want to submit to the same directories, use your other keywords as anchor text for the links in your articles. This way, all the links will count towards a different keywords, thus giving you a better search engine ranking for those keywords.
I know many of you guys know this already, but some might simply forget about this simple thing and over look it. Hope this helps out.