"iMessage, on the other hand, replaces SMS. It's the one and only way to send text messages on the iPhone and it will avoid SMS whenever possible. Users won't e

"iMessage, on the other hand, replaces SMS. It's the one and only way to send text messages on the iPhone and it will avoid SMS whenever possible. Users won't even think about what underlying protocol they are using." Now that is a great point. I wasn't aware that iMessage replaced SMS entirely. I assumed that it was a separate app. I don't think the impact of it being the default method of sending messages can be understated.