Articles directories are a great place to put your articles so that they will make you money. You can see the results when your website receives more hits - first, somebody or a few people would see your article, then they would see it is well-written and hail you as an expert, then they would click over to your website. If writing does not happen to be one of your skills or aren't too skilled about the subject matter of choice (maybe you run an affiliate), then hiring a writer would be a very viable option for you. Take note though that the best writers out there can fetch an expensive price tag, but hiring their services will be like the gift that keeps on giving - affiliate sales and/or your own sales should rise, resulting in nothing but mucho dinero for your online enterprise.
Let's see how this would work out in real life. Imagine that you are an accountant working from home. Feeling bored one day perhaps, you write an article about the wonderful world of accounting and submit it to different article directories. And mind you, people need accountants, especially during tax season - they will search for subjects related to your article, read it, think that you know what you're talking about, and respond by sending you an email or visiting your website. Your article just gained you a new client who may use your services regularly, but will definitely give you a nice profit at least once.
Furthermore, since you have posted it on a free article directory, others who have affiliate websites about accounting will inevitably use your article for their website. These affiliate webmasters all made it a point to use his byline, and gave his online presence a much-needed boost by including the byline when reposting. This because you will be benefiting of off the traffic that they get to their website.
The 'net is teeming with article directories for you to use at your discretion. Your bet best is to put a copy of each of your articles on every one for maximum exposure. At the end of the day, you get more traffic, more customers, more orders and best of all, more money.