IMs had that feature in the 90s, so at least for the digital era it's not abnormal for most of us. Professionally, we use read-receipts in emails in my office.
I don't mind IM's showing the 'read' bit, but for some reason I've always found read receipts on emails rude, and when it pops up the prompt to send the receipt back I always hit 'Cancel'. I wonder why.
