In my limited experience (watching American TV rather then personal experience), I have noticed when people end telephone calls in US television programs they tend to say what they have to say and then hang-up. There is no wrapping up with ‘see you later’, ‘bye for now’ type stuff. Is this what really happens or do people in the US normally sign off a telephone call with Goodbye or something similar. In the UK and Australia, people always end a call with some form of farewell remark and to not do so could be construed as blunt and bad mannered.
I had a boss who was Canadian and she would always end her calls quite abruptly. To the point where a number of people mentioned it but we put it down to a cultural difference.
I notice you wrote that you sometimes write nothing when ending an email @augustlan and I wonder if this is a continuation of a similar communication trait to telephone courtesy? Is it common for people in the US to just finish an email and not to sign off? If of course the television portrayal is accurate, which it may not be! I’m just wondering if this is a cultural difference?