Content aggregation and ranking engine StumbleUpon is releasing a new widget for publishers today that can be placed on a website or blog to help users find meaningful content relevant to them.

The StumbleUpon Widget can be used by publishers to surface content on the site with the best shelf life. The widget will come in three sizes and requires a line of script to be embedded on to a webpage. The widget will surface stories and videos suited to the users' interest based on what has been rated highly by the StumbleUpon community of 15 million users.

When a user is on a page with a StumbleUpon widget installed they will see links that are tailored to their interests. The company touts the widget as a way to fill unsold ad space on and spark interest in exploring the site, thus increasing page views and time spent consuming content.

StumbleUpon claims to be the largest non-Facebook referrer of social media traffic. The company is not specific, but that would likely include Twitter, Reddit, Digg, XYDO and other similar tools for publishers. As of April 2010, StumbleUpon funneled twice as much traffic to publishers as Twitter. The user base is predominately between 18 and 34 years old and split 54% male to 46% female.

StumbleUpon has a couple of other publisher products as well, including badges (which look like any normal share button) and a URL shortener (su.pr). The company claims that publishers get 20-25% more traffic from StumbleUpon when they institute badges.

There are a few drawbacks for publishers. A lot of publishers choose to self-aggregate content within posts or certain locations within their sites. The StumbleUpon widget would take that control from them and automate through the company's index. Another drawback is widget/badge/button fatigue. Share buttons and third-party widgets have to be maintained by publishers and the more of them there are, the more of a time-consuming process it becomes. While the StumbleUpon widget takes up space where there would otherwise be nothing (or unsold ad inventory), it is another piece of real estate on the page.

Increasingly, it is hard to justify clutter for the sake of utilizing empty space. Facebook and Twitter both have widgets as well, and those ecosystems have millions more users than StumbleUpon does. Sometimes, simpler is just better.

If you are a publisher, does the StumbleUpon widget seem like a good idea? Do content consumers care about clutter on a page? Let us know in the comments.