> Email and SMS aren't reliable, you've no way to know if they've been read. Most people do not want this feature. 9/10 of my iMessage contacts turn off read r

> Email and SMS aren't reliable, you've no way to know if they've been read. Most people do not want this feature. 9/10 of my iMessage contacts turn off read receipts; I bet the number would be similar on Facebook/Whatsapp if they allowed it.