Not sure if it is a bug or feature, but searching my domain with and without "www" produced different results. I expected actual website to be the first in both

Not sure if it is a bug or feature, but searching my domain with and without "www" produced different results. I expected actual website to be the first in both cases. http://duckduckgo.com/?q=news.az&v= http://duckduckgo.com/?q=news.az&v= http://duckduckgo.com/?q=www.news.az&v= http://duckduckgo.com/?q=www.news.az&v=