StumbleUpon is a social bookmarking site with a feature most (if not all) others lack… you can choose categories of interest and then "stumble", which takes you to a page that someone else bookmarked in one of those categories. It can be a fun way to kill time when you're at the computer and bored. It can also, and this is the focus of this article, drive a lot of traffic to your website.
StumbleUpon users can, and do, click the button to go to the next page unless you grab their attention quickly. Pictures can help with this, as can a good site design. Probably the most important, however, as with most ways of generating traffic, is your title… if you have an interesting title, you can grab their attention, and get them to read more.
So now that you have their attention, what gets them to give you a thumbs up? One of the easiest things to get a thumbs up for is a picture, preferrably a funny one, but interesting or beautiful can work, as well. But since this isn't a photo blog, I'm going to go more into what I've found works with written content.
StumbleUpon users, or "stumblers", tend to like content that is easily digested. Most of my articles that have gotten the most thumbs up, and the most traffic, are simple to understand. I get a few votes for my more in-depth articles, but two of my top three articles even have "Simple" in the title: How To Make Your Life Happier In One Simple Change and The Very Simple Secret To A Happy Marriage.
That doesn't mean that the content is shallow and meaningless, however. My top article, A Potentially Fatal Mistake, is about how low self-worth leads to depression, not low self-esteem. It's still easy to read and understand, however.
So easy to understand content on a topic that is commonly (or even more so, currently) discussed, laid out in a reasonably attractive manner, with a good picture and headline to catch their first attention will often do well in StumbleUpon, bringing you thousands of visitors in a day or two, with the traffic continuing in dribbles after that.
Bonus Information: The headline is how many page views StumbleUpon has brought me so far this month… but it's misleading: StumbleUpon loads the stumbled article twice for each visitor it sends your way by default, artificially inflating your page view count. This option for "pre-fetch" can be turned off, but it very seldom is. If you want to know how many actual people saw your article, divide the StumbleUpon traffic in half… in other words, for 17158 page views, StumbleUpon sent me roughly 8500 visitors.