Knock, knock, hello? ARE YOU THERE? ANSWER ME DAMMIT!

Most times I would write back, sometimes I do not if I have nothing to say or if I am in the middle of something. I don't think I am unusual in this, it seems to be how most people behave. Text messages and IM conversations are not synchronous communications. For example I would not simply ignore somebody if they were standing in front of me or talking to me on the phone. But that's the beauty of the asynchronous text and IM messages, it allows that.