[wp_scm_mashable_stumbleupon]
With the "Explore Box" feature, users can Stumble pages related to hundreds of thousands specific topics -- like Vincent Van Gogh -- instead of working within about 500 set categories -- like art -- that StumbleUpon has stuck to in the past. It's as though a search engine and a "best of" list had a child. If StumbleUpon hasn't sorted the exact term you're looking for, it will match you with the next best thing.
Right now the feature is restricted to a small search bar in the browser product. But despite the minimal presence on the homepage, it's a huge change for StumbleUpon.
In the future, StumbleUpon CEO Garrett Camp says, StumbleUpon will integrate Explore Box's technology with its follow feature so that users can Stumble a mix of general and specific topics. That will make the discovery engine a lot more personalized, and eventually (though Camp says probably not anytime soon) enable StumbleUpon's advertisers to more closely target their ads.
“We’ve had to basically rewrite the recommendation engine,” Camp told Mashable. “Even though it seems a lot of work going into one feature, that one feature is going to influence the entire experience.”