When you send someone a message in some messaging system which has read confirmations (like whatsapp, for instance, or outlook), and the message is marked as read (or you receive a message read confirmation, or whatever equivalent your messaging system has), but they never actually reply, which often implies that they don't want to (or can't be bothered to, same difference). Whatever the case they probably don't have as much respect for you as you have for them.

As a metaphor I suppose it can also mean doing something for someone without getting anything in return, even though reciprocation would normally be expected.