Come on, we all know that doesn't mean it's getting as wide use as a search engine as Google let's say. And popularity doesn't mean that it's not leaving things on the table. I'm just trying to give feedback as a potential user from a non-technical perspective, which I think most developers overlook.
You can't beat Google by trying to be Google without having Google level money, and even then, you still probably can't, Microsoft and Yahoo tried.
So, do something different. It's possible to grow by endearing yourself to geeks first. How'd Firefox catch on to begin with? Geeks, then they recommend to family and friends etc.
Hell, even if geeks were their only users, it'd likely be viable. There are a lot of us.
Except for searching, right? I mean what is the average number of links which DDG returns you for your ordinary search query? Is it even close to Google's results? And what about it's relevance?