To expose to more readers beyond HubPages is to use social media. Share at Facebook, Flipboard, Google+ and use Twitter. Some use Twitter too. The most valued traffic with the greatest longevity or constant feed is from search engines like Google.
There is a bit of an art to gain growth of audience and a steady stream of readers. That is known as Search Engine Optimation (SEO). The goal is to get a high page ranking. In other words where the article is for a search. The basic keys for it are:
Keywords for the article
Keyword usage in the content
Not stuff the article with keywords
An optimal title around 55 characters with the keyword(s) in it
And, importantly article quality
SEO can be complex and a science if researched online. Keep to the basics is recommended for a Hub by most in the forums. BTW . . . you may find more with experience at the Forums with suggestions. I recommend posting in the 'Getting Help from the HubPages Community'.
Here is a link to a HP article discussing self-optimization
Here is a Link to the HubPages Learning Center. There are other helpful articles there as well there are those posted by Hubbers. Use the Search queue above and peek for them.
Learning Center: https://hubpageshelp.com/