StumbleUpon will bring more eyes to your site, but visitors who come from SU tend not to stay on a page very long, so the quality of the traffic won't be as good. You can post your image-rich articles to Pinterest, but you need to be active on the site to get others to re-pin your content. Another way to build backlinks quickly is to answer questions on Yahoo Answers and include a link back to your hub as a resource.
The best way to get traffic is to do a lot of on page SEO that makes your hubs rank higher in the serps. Make your titles unique but include a keyword or two. Use keywords and their synonyms within your article and subheadings. And most important, be patient. The age of a page affects traffic.
One thing to avoid is spamming FB, Twitter, Digg, etc. Mass-posting links there really won't bring a lot of traffic to your site.