[NewsPoster]

Apple is currently handling about 40 billion iMessages (including push notifications) per day, and about 15 to 20 million FaceTime calls, CEO Tim Cook disclosed earlier today during the company's annual shareholders meeting. That indicates exponential growth during 2013, since in January of that year, the company was only up to 2 billion iMessages a day. Apple just recently added audio-only FaceTime calls as an option for iOS and OS X, which could grow traffic even further.

iMessage is said to handle "billions" of its own messages per day not including the push notifications, but is still playing catch-up with WhatsApp, the multi-platform messaging app now owned by Facebook, which sees about 50 billion messages each day (though a huge number of these messages are handled as push notifications, contributing to iMessage's total). It is also well in excess of BlackBerry Messenger, which despite being multi-platform, processes about 10 billion messages daily.

Exponential growth...e^x? Sounds like mixed messaging to me.

[carloblackmore]

I'm not sure what changed (if anything), but I'm actually noticing more and more people walking around on FaceTime calls. Maybe it's just gradual adoption due to more powerful processors in the 5S? Or as simple as the icon being changed to bright green to match the Phone icon?

[DiabloConQueso]

If they're walking around, it's likely due to the lifting of the restriction that FaceTime calls only be done over wifi networks.

With the ability to FaceTime over 4G/LTE now, perhaps that's why you see more people "walking around" (which I assume means "out and about") using FaceTime where there may not be a wifi connection.

[Salsa]

And.reg, are you saying that you cannot distinguish exponential growth from linear growth with only two data points? I would agree with that. Technically, linear growth can be very steep. It is only exponential if the growth accelerates over time. The author probably thinks it is exponential because it more than doubled in a year, but as long as you can draw a straight line through all your data points, it is linear.

[Spheric Harlot]

We have three data points.

If the company was up to 2 billion a day in the 14 months since the introduction of iMessage in October 2011, and grew to 40 billion a day within another year, then growth is not linear.

Originally Posted by Salsa 

And.reg, are you saying that you cannot distinguish exponential growth from linear growth with only two data points? I would agree with that.

They're just models, so any one of a zillion "fit functions" could describe messaging growth into the following year.

[Spheric Harlot]

We have three data points.

I think we're all making the same points.

[Spheric Harlot]

I'm making the point that you don't have one.

Gosh... It's a large number, btw.

Originally Posted by Spheric Harlot 

I'm making the point that you don't have one.

I do have a point. Re-read my post.

It's because there are three data points that any of a zillion models could predict growth.

[Spheric Harlot]

Originally Posted by And.reg 

I do have a point. Re-read my post.

It's because there are three data points that any of a zillion models could predict growth.

Oh?

So…
Between point 1 and point 2: some growth.
Between point 2 and point 3: growth about twenty times as fast.

What do you think might have happened in the meantime?

I dunno about you, but when I look at other known numbers that correlate, like, say, number of iOS users over time, I get the impression that nothing BUT an exponential curve could possibly apply.

Originally Posted by Spheric Harlot 

Between point 1 and point 2: some growth.
Between point 2 and point 3: growth about twenty times as fast.

And where do you expect point 4 would land?

Originally Posted by Spheric Harlot 

What do you think might have happened in the meantime?

Like you keep insisting, we only have 3 data points,

...therefore, no one really knows.

Feel free to reply once MacNN doesn't keep giving these stupid "the server is too busy" error messages.