Adding links to your hubs or your profile page will help improve traffic. Not all sites will allow you to post links, so it will take some searching. One of the sites I use is Stumbleupon, but there are tons of them out there. You can also add good links in your profiles on google, yahoo, pinterest, youtube, and many more. When filling out profiles on big sites, always look for a place to add a link, and make it a link to your hp profile. This will use these important links to direct visitors to your profile where they can access all of your hubs. Many times these are the much sought after "do follow" links.
I am no expert, but these few things have helped me out. Also, this may be obvious, but it helps to be active on hubpages. It seems that you are already doing this, as you have a lot of followers. Reading and commenting on the hubs of others and following other authors will help you build a better fan base. I have put you on my follow list to help you a little more:-)