I agree with this, but mostly because 'hello' is a demand for synchronous communication, whereas just dropping your question off means you can walk away and the

I agree with this, but mostly because 'hello' is a demand for synchronous communication, whereas just dropping your question off means you can walk away and the recipient can handle it at their convenience. Of course, chat has mostly supplanted email at companies I've worked at and as a result it is used for both sync'd and async communication.