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A Bit of Self-Served Claim Chowder Regarding iMessage and Phone Numbers as Identifiers

One last bit of behind-the-scenes follow-up regarding the production of The Talk Show Remote From WWDC 2020. For help with my audio setup, I worked with Zach Phillips. Phillips is local to Philly, an audio engineering ace, has worked with Sandwich before — and, it turns out, I linked to his blog back in April 2012.

Even better, he was right and I was wrong. Although he was wrong too. It’s actually an interesting post worth revisiting.

Phillips argued for allowing Messages for Mac — which had just been announced, but not yet released, as part of the then-forthcoming Mac OS X 10.8 “Mountain Lion”1 — to use your phone number for iMessages. I thought this was a terrible idea, on the grounds that I was stuck in the mindset that iMessage for my phone number was purely a replacement for SMS, and that iMessage for my Apple ID email address was a replacement for instant messaging like AIM, and the two use cases shouldn’t mix. Wrong!

Phillips, unfortunately, was wrong too:

iMessages, as an enhancement to SMS, should never use email addresses.

So I thought iMessages addressed to a phone number should only go to your iPhone (and not your iPad or Mac, let alone your Apple Watch (which was years away from being released) or glasses (which remain years away now)), and Phillips thought iMessages should go to every device, but should only use phone numbers as identifiers. I’ll score this as me being very wrong, and Phillips being a little wrong.

What we both missed is that messages aren’t between phone numbers or email addresses or specific devices — they’re between people. Phone numbers and email addresses are just identifiers used to address those people. One person can have multiple addresses — easy. (Sort of.)

Just about everyone today acknowledges that iMessage’s usurpation of text messaging from the carrier-controlled SMS was a stroke of genius on Apple’s part, but I think few appreciate just how deft their strategy and execution were. What we initially saw as “free SMS for iPhone-to-iPhone text messages” was really the bootstrapping of an altogether new (and secure) worldwide messaging platform — a platform that today is an immeasurably valuable asset for Apple.


  1. Mountain Lion had a rather unusual rollout. Apple announced it out of the blue in February 2012, via private press briefings. Such briefings were new, for Apple, at the time. Apple then revealed more details and released a developer beta at WWDC 2012 in June, and the release version shipped to everyone just six weeks later on July 25. My piece on my February briefing is one of my favorites at Daring Fireball, but wouldn’t be possible today — Apple’s agreements for such briefings now typically preclude discussing the circumstances and trappings of the briefings themselves. It’s like agreeing to write about a movie, but not the experience of the movie theater in which you saw it. ↩︎