I think they all good if you know how to use them correctly. Content is the key to generate more traffic, is that what you are after. It does not matter which social network you use as long as your content is good. All the best.
I've use Stumbleupon and I found that Stumbleupon has an essential role now in these days here you can find follower or fans in massive numbers for generating traffic on your website, and I'll vote for Stumbleupon.
Thank For your Reply ... i think so stumbleupon good than hubpages, coz hubpages deleting old posts..
Hubpages is completely different concept than stumbleupon. Stumbleupon is a social networking site while hubpages is a content writing platform. Both of them requires different skills to get traffic. By the way after Panda update hubpages was badly hit and lost its rankings. Now the site is not worth writing. If your posts were deleted, it would be because of poor quality content.
Valeed is right on with that he put. Both require different skillsets to get traffic from. If you're using stumbleupon make sure that your above-the-fold is super eye catchy to draw the users attention. If you use Hubpages, write good content and it will reward you for the long-term. Think of using either of those as an inbound marketing method to draw in traffic. Another option would be to use Examiner.com for content marketing. It get's well over 17+ million unique visitors / month and typically can rank pretty high in the search results. If you want, I wrote an article on how to sign up and get approved on Examiner for inbound marketing ( http://www.bigbrandexaminer.com/inbound-marketing-how-to-leverage-one-of-the-top-2k-alexa-sites-for-seo-traffic-generation/ ).
I write for the Examiner, and I'll usually had links back to my other sites, but they're all related (I write mostly about auto recalls). As far as Hubpages is concerned (and Stumbleupon for that matter), does the content have to be original? Or, could I syndicate content from a site on there? (PS I had to take the link out of the quote, because DP wouldn't let me post this otherwise)
Well StumbleUpon have nothing to do with Hubpages!! StumbleUpon is a social bookmarking website while Hubpages allows you to make money online by writing articles so what you are comparing exactly!!! you can't compare Ebay and Google+ for which one is bringing more traffic! I know you would be asking, can I generate traffic through Ebay?? well yes, if you have a sales page but that doesn't mean that you can compare it with Twitter. At the end, there is a lot of ways to generate traffic, and as each one of us unique and each blog unique, the same way might not work for all of us. You will always find below generating huge traffic from Facebook, while others only get few views but they get more on Twitter. So test by yourself and check which one works most for you.