2) SEO has made search for some items really lousy. Some way of filtering those results out might be handy.
3) Sometimes people just need a quick answer to a question. "What's the population density of Manhattan?" is reasonably easy to get an answer to, but "What's the name of that TV programme I used to watch in the 80s with a character called something like flimby or flombu and it was a steel egg thing" is much harder to search. (It's a demonstration of just how good search is that I can bash in a few keywords for such vague queries and get useful answers.) Uh, so some sites try to solve this by letting you ask a question and have humans answer it (Yahoo Answers; Stack Exchange), but still a best search engine would be better at finding these kinds of answers.
4) I make a post to Facebook. Or I see a post on FB. A few weeks, months, later I want to find that post again. But I have no hope.
5) I have about 3 million bookmarks. They are untagged and poorly named. I want something to crawl those and build an index, so that I can then find the URLs I want.
1. It is more vertical. Allows for deep search with filters. 2. Ditto. It uses hashtags, forward slashes and bangs. All with a different functionality. 3. I'm up to my neck in machine learning to improve this. 4. It allows for you to search your own posts. Yes, you can post to Nuuton. No, its not a social network. 5. It allows tagging with hashtags. Say #pizza #recipe.
Plus its available as an API.
I disagree about the flat search engine being outdated. I hate all the social crap, videos, and local listings the big search engines shove down your throat. I've heard a lot of other people voice the same concerns.