If your goal is to get your website or web page indexed in Google, then the answer is one article. You can start seeing results with as few as one article. If your website is not even indexed in Google yet, all it takes is one published article. It is best if that article is published at a website with a decent amount of Google PageRank. That helps to speed up the indexing process. Once your website’s pages are indexed, they will begin appearing in the search results. If all you have is one link pointing to your site, then how well your pages rank will be determined by how well optimized they are from an on-page SEO standpoint and by how many pages you have on your site that point a relevant link at any given page.
What if you are using articles to build links for SEO?
If your goal is to get your web pages ranking well through link power, then you are going to need to get a higher number of links. It really depends on how powerful the links are that you are getting. If the links are coming from common public article directories, then you will need many of them from many different places. If the links are coming from trusted blogs within your own niche that are well known and have a lot of Google PageRank, then it will take far fewer. You should plan on getting an absolute bare minimum of twenty different websites linking back to yours before you can start seeing real results. If your niche is really competitive then you are going to need a lot more than that.
With this website I was pleasantly surprised to see that I got page one ranking in Google with only fifteen articles published at other websites. I expected it to take more than that. You should expect it to take more than that with your website. But hey, you never know. If I got those kind of results with fifteen articles competing for a relatively strong keyword, then there is no reason why you couldn’t get that good of results also. I downplay my results a little bit because I know that getting those kind of results with fifteen articles is not very common, at least not in my experience.
Some Advice about Article Marketing
If your goal is to use the articles to help get a site ranked as high as possible, then you should publish your articles at as many different places as possible. If you are trying to duplicate my experience, don’t publish those fifteen articles all at one place. Instead, you should publish each of them at a different website. You want to get as high of number of different sites linking back to your site as possible. That builds up your ranking faster that getting fifteen links from one other place.
I tell people to think about article marketing as if they were building a house out of bricks. Each article is just one more brick. The more of them you use to build your infrastructure, the stronger your website’s position will be in the search results. Even if you get as good of rankings as quickly as I did, you should keep writing and publishing new articles at new places to further boost and further solidify your positioning.