Goal #1 should be high quality search results while respecting privacy. Everything else should be secondary. The biggest thing DDG could do to improve their product is make it quick and easy for users to provide feedback about bad search results. I'd be happy to report searches that Google gives better results for but they don't have a mechanism to do so.
For example, search DDG for "odroid". The official domain is hardkernel.com. The first result from hardkernel comes up at #6 for me. I'd love to have a way to suggest the official domain for a product like that so it shows up as #1.
As someone who mainly uses DDG when Google decides to block me for "searching too hard", one thing that would make me switch over to DDG completely is advanced search operators --- boolean expressions, exact match (no, not the stupid sort-of-exact one Google has), etc. Basically features that will let you "grep the Web" the way old search engines do, and what new search engines are even trying to forbid.
Also, if I input n-number of words then search for those words.
Recently DDG has been Googleifying by dropping one or more search words with an explanation "Not many results contain ____". So I have to click a link to search again for the words I entered. Quite annoying when it happens repeatedly each day.
The problem is that isn't how things are indexed, so "grep the web" is a hard problem. Grep on your machine just scans through every byte, doesn't care how long it takes, and doesn't care how much computing resources it uses (preferably, as much as it can).
Their bangs are genius in that they already provide a natural way for you to give feedback without actually having to think about it - rerun a query with !g, and they will redirect you to Google. Good for you, good for DDG, since they can tell which queries provide insufficient results.
Of course, you can't suggest the correct result for a specific search term, because search engines don't do a one-on-one matching of terms and results. But this will allow them to analyse at what types of queries their engine performs badly, and to improve it there.
(I don't know if they actually do this, but the theoretically can and should.)
Thing is, bangs are for people who don't use launchers (Alfred, LaunchBar, QuikSilver, Launchy, Gnome Do, Unity Dash, etc.) with web search functions. To redo a search for me: Cmd-Space, Up, Return. To add a bang to a failed DDG search: click in a search bar, make sure the whole search text isn't selected so it won't be replaced, remember which bang I want, type it in, return.
Those who don't use launchers outnumber us greatly, of course. But by virtue of being able to specify an alternative search engine using the same efficient keyboard commands as everything else, bangs aren't much more than a pain in the butt.
Even putting launchers aside, not every DDG user is going to use bangs to get results from another site. I'm sure many, as I, have the muscle memory to bring up google.com in the flash of an eye, whereas awkwardly clicking in a search bar to type in a bang surely can't be used by even the majority of DDG users.
(Of course, I don't have data to back me up, but say DDG became as ubiquitous as Google, this would be unquestioned. All the users' habits in organisations where Qwant is set as the default could make an interesting data set — except, of course, it wouldn't be possible to track who used what)
tl;dr: Bangs are too inefficient and usage must be too inconsistent to use as the basis of improving the results.
FWIW in the cases where my DDG results are insufficient (which is happening a lot less often than it used to), I try to just go up and insert a "!g" before the same query.
I don't know if DDG is looking at their "!g" requests or not, but I'd be surprised if they weren't.
Combined with that they could collect locally relevant information too.
Using DDG from the UK is currently a disappointing experience. You have the choice between US centric search result or "UK" filter that is too restrictive: for example "man cat" with the UK filter return mostly non unix stuff (unlike the default version)
!g is great, but when I use DDG on my iPhone, "!" is not an immediately accessible character.
Thanks for the suggestion. We implemented this earlier in the year for desktop users, so on the right-hand side of each search results page there's a "Send feedback" button which goes straight to the developers.
There's a "send feedback" button in the lower-right corner that does exactly what you're describing (I think it's hidden in the sidebar in the mobile version). I'm not sure how closely they actually pay attention to the feedback, but it's still worth doing.
Send feedback is not a simple process. The link takes you to a generic feedback page with fields you have to fill in. It should be much easier to report bad results.
We're working to improve our feedback process, but as mentioned, we have a "Feedback" button at the bottom right of every search result page.
Clicking this opens a form right on the results page which you can use to specify what the feedback is about (link results, image results, ads, etc.) and why you're happy/unhappy with what you're seeing.
I know I wasn't. Every time I try DDG, I immediately switch back to Google. DDG returns utter garbage when I try to do searches whose terms mix two or more languages; considering I study literary translation and am learning a few languages at the same time, this is fairly common.
I've a feeling that a lot of DDG users must be changing their search habits to suit DDG's engine, but I and plenty of others just can't.
They are as good as Google for me, sometime slightly worse, sometime slightly better, and I didn't even change my searching habits when I switched.
Also you can turn on or off localized results easily if you need to, which is hard with Google.
The only thing I'm really missing is the good completion while typing.
I really don't think that the results on DDG are inferior, but I'm comfortable with the results. If I want something more personalize or near for my location(Venezuela is not available on DDG) I just go to Google directly or with !g
I actually think that breaks it, I like it better when everybody gets the same results for the same queries. People (via algorithms or directly) shaping what others get to see, rather than configuration and user empowerment, is something I reject.
For example, search DDG for "odroid". The official domain is hardkernel.com. The first result from hardkernel comes up at #6 for me. I'd love to have a way to suggest the official domain for a product like that so it shows up as #1.