When I first started to use Duck Duck Go (DDG) it was due to being a bit of an Apple fan boy. Apple were moving their default search engine to Duck Duck Go and I wanted to give it a try.
My original thoughts were that because of it's privacy policy - it would not share your information with third parties. Of course this is a great feature, but it's not the reason I use Duck Duck Go (nor is the fact that Mr Duckface is absolutely adorable).
I will admit that Duck Duck Go is not the perfect search engine for it is still young and needs more time to improve. I very occasionally still use Google to search for things, but the majority of my searches are through Duck Duck Go.
No the main reason I use Duck Duck Go is because of the features they have started to add. I play a lot of Minecraft and I spend a lot of time reading stuff on the Minecraft Wiki. I also read a lot of Wikipedia articles. Duck Duck Go is the perfect search engine for anyone who does this kind of stuff. Why? Because Duck Duck Go takes a standard search over to the search page of a certain website.
Say I want to look up how to make a sticky piston in Minecraft, I would simply type into my search bar in Safari:
!minecraft sticky piston
And because Duck Duck Go is my default search engine I will be directed to the Minecraft Wiki searching for the term "sticky piston". This saves me a whole page or two of searching.
I have also changed my personal website to do this too. Now instead of typing "blog: google" to search for "google" in my blog only, you type "!blog google".
So go on, Duck It!