[low_battery]

Basically DDG is at the mercy of their sources, they can proxy the results for now to the actual search engines, but what happens if lets say Bing and Yandex requires them to pass some extra stuff or cut the query hose otherwise? Will DDG use its own index? Please.. They have no resources to build an actual half decent search engine.

[nickpsecurity]

I agree. Being effective and independent will cost money. There some potential for a company that charges monthly or annually to provide search services to other companies with privacy. There's lots of search, like marketing or competitive intelligence, where companies would prefer that the terms don't go through a surveillance company. Initial results might do as DuckDuckGo is doing now with them incrementally building their own database as funds came in.

Not sure how marketable it is, though. Google is pretty dominant. Most companies already running their stuff through it.