There are many short answers to this question. First, do you mean traffic from fellow Hubbers or traffic from search engines? If you mean from other Hubbers, I find that when I read and comment and follow on other people's Hubs they tend to read and comment and follow mine. I wrote a Hub on this topic: http://hubpages.com/community/So-You-Want-To-Be-A-...
In regard to search engine traffic, there are a few elements that define traffic. The highest viewed articles are original, and are often popular user-searched topics that aren't over-competitively answered on the web.
The more articles on a particular subject, the less likely you will be ranked high in search rankings, that is unless your article has richer content. Also, it takes a while for search engines like Google to "find" articles, so it may take a month or even a few until your rankings increase. I recommend visiting the HubPages Learning Center for more information on this. Here's the link: http://hubpages.com/@learningcenter
I hope this helps!