Currently the !translate bang redirects to Google Translate using auto detection for the input language and english for the output language.
It would be great if DDG makes use of the Accept-language HTTP header to automatically set the output language when redirecting to Google Translate (independently from the language DDG setting).
A very large number of forums on the Internet are powered by phpBB.
The pages of such forums are by default presented in a different way to users and search engines (which by the way is a very bad practice, even if the text content is the same). The "Hi-Fi" version, shown by default for users shows images, avatars, CSS styling, etc. but the "Low-Fi" version, sent and indexed by search engines, has only very basic HTML and CSS.
Currently the 3 main areas that make DDG specific are : 1. privacy 2. 0-click info 3. less spam in the search results
The first one is very well explained on this page, the second is quite obvious if you do a random search, however the last one can be a bit obscure.
A good way to demonstrate this could be to add an example of query that shows a lot of ads on Google, and the same query done on Duck Duck Go, to show how the result page is cleaner. Because some users are using ad-blocking in their browser, and totally forget that Google SERPs are full of ads, also show another page where there is obvious SEO spam in the results. I also think it would be great to explain a bit that there is a DDG specific technology to detect and remove spam in the results, without giving too much details of course. I actually learned about it in the Youtube interview posted on this forum, and it does not seem to be documented on the site.