There are plenty of webmasters and website owners who write hundreds of articles but this ends up having little or no effect in terms of promoting their websites or affiliate programs. And then there are people who write a single article that ends up generating tons of valuable targeted traffic for them.
While your writing style is important the truth is that what really makes the difference is the focus of your articles. If for instance you start your research for the articles by finding out how the product or service is sold and the most effective methods that have been used to sell, you will be way ahead of the pack.
Write less for much more traffic.