If I understood well I would say that id depend on the medium. If I'm asking a question by email I expecte to have an answer in 2/3 days. But if it's a chat (specially a chat box) I expect it to be in a matter of minutes. The same for IRL, if it's letter I dont mind waiting weeks but in a line a few minutes..
I don't think it should be online/offline but more about the situation and the medium
I don't think it should be online/offline but more about the situation and the medium