It's a general purpose search engine, designed to be a drop-in replacement for the majors. However, it does have features that should appeal in particular to schools, homes, and people doing a lot of what is x searches.
Traffic has grown steadily over the past year. While there isn't strictly a need for a new search engine, some decent % of people who try it out like its unique features.
While I don't understand why people need this search engine, I am impressed by the traffic this site is getting.