The goal of this site is nicely put at their overview:
Up to 25% of all news articles written in any given day are based around some kind of statistics. Many times when we read one of these articles we want to remember a particular statistic without bookmarking the entire page. Search results still require you click a link and read through paragraphs before we find the relevant number. In some instances, statistics are described in different way but are logically comparable. Search engines have a hard time returning all of the relevant statistics and projections because of the nuances of language and thought around forecasts and projections.
For the most part the numbers that are there are taken directly from news articles; what I'd like to see would be something that explains where a given statistic is really coming from, a sort of provenance for numbers. (Of course, one can presumably do this by tracing back to the original source.) This would be nice because then one could know when two statistics are comparable; I want to know if I'm comparing apples and apples, apples and oranges, apples and hamburgers, or apples and televisions. (Televisions are obviously very different from apples, because you can't eat them. I was going to say "apples and computers" but then saw the potential for misinterpretation.) Of course, this would also require a lot more work, and a lot of the time you just can't tell where people got their numbers from. It appears that the software includes the feature of "discussing" a given number, though, so this might naturally evolve if the site takes off as people begin to see numbers juxtaposed and wonder what to make of it.
The nuances of language as they apply to various questions of forecasting and projecting might be lost on people, too. It's interesting how logically equivalent questions can give much different results in political polls, for example.