Firstly hello to all the people that have got to this page via Stumble upon. 
Right then, I recently created a post about 10 tips to succeed on YouTube. And thought I may aswell stumble it over at stumble upon. This was mainly down to word of mouth and hearing that you can get some good spikes in traffic. As you can see in the image below, that was the truth indeed.
That’s an uber spike in comparison to my normal traffic trends.
Tip 1 – Make sure your content is worth submitting, the last thing you want is someone giving the page a thumbs down and burying it within the depth of Stumble Upon’s rubbish.
Tip 2 – Build up a small network on Stumble Upon say 15 to 25 users. You can do this by going onto the site and looking up users that have Stumble’d pages that are of similar interest to your site.
Tip 3 – Get users in your available on your favorite IM client, that way you can ask them to Stumble your page for you. It obviously looks better if someone else stumbles your content too, also vary the people that Stumble your pages. It will eventually look a bit suspect if the same people are stumbling your content.
Tip 4 - Maybe offer some free stuff, competition or something viral and cool. This is the kind of content people like and are likely to give a thumbs up to.
Tip 5 – Offer up a welcome message for all people that come to your site via Stumble Upon, see I have one at the top of this post
And then monitor your analytics. I have heard stories of people getting up to 8000 plus hits from Stumble Upon
Apologies for the brief post one day I will go into more depth with Stumble Upon.