Global Search Box as Question Answering

During a product design session, we had a discussion on Global Search covering “what search is” and “what search should be.” I used the following example of question answering as where I see “global search” heading:

I can search Google for US population and it will give me an answer

I can also search for 2014 google revenue

I can even ask Google about revenue in the form of a question: how much money did google make in 2014

However, when I asked a question requiring a computation, I got search results and not an answer:  2014 google revenue per US population

When I ask WolframAlpha that same question, I got an answer: