Michael Gartenberg Michael Gartenberg has covered the personal technology beat for more than two decades at places like Gartner, Jupiter Research and Altimeter Group. Most recently, he spent a few years at Apple as Sr. Director of Worldwide Product Marketing.

Only when Apple can explain — and justify — iPad's existence amid the pantheon of Apple devices will we see both clarity and growth in the market.

When something exceeds your ability to understand how it works, it sort of becomes magical.

[iPad is our] most advanced technology in a magical and revolutionary device at an unbelievable price.

— Steve Jobs, iPad introduction, 2010

There's a second group of people that we'd love to reach with this iPad Pro: Windows users. There are over 600 million PCs in use today that are over five years old. This is really sad. It really is. Many of them will find [iPad Pro] is the ultimate PC replacement

— Phil Schiller, 9.7-inch iPad Pro, introduction 2016

iPad has always been hard to quantify from a usage perspective. iPad as a category was so revolutionary many were dismissive or predicted failure when it was introduced. Was it a device primarily for content consumption, and entertainment? Was it a tool designed for content creation, and productivity? Was it something new entirely?

Certainly the marketing message has evolved. It's gone from iPad as a new device category to a Windows PC replacement (and, by that logic, perhaps a Mac replacement as well?)

The evolution of that message isn't contradictory, though. The key to understanding iPad — and iPad's success — is understanding how Apple crafted an experience that is better than a personal computer or a smartphone for many tasks.

That's right: iPad is not just a scaled up iPhone and it's not just a derivative of a two-in-one Windows PC.

Combining multiple devices such as a tablet and a notebook may sound good in concept, but the reality is a deeply compromised experience the, in my opinion, leads to a poor PC and a poor tablet. In contrast, iPad was the opposite of compromised — it was and is optimized.

I'd argue that iPad isn't really a Windows PC (or Mac) replacement either. Those aging PCs are perfectly good enough to perform the basic computing tasks most people require. So, it's not iPad vs. PC. Rather, It's how to be most capable and productive going forward. That's where iPad shines.

iPad unlocks new capabilities and functionality not available on a PC or a phone. It does that with the largest collection of tablet-optimized apps in the industry, and how with adjunct accessories such as the Smart Keyboard cover and Apple Pencil.

The result? iPad is a force multiplier for the PC and phone users already own. That's the story I think Apple needs to articulate to customers. Only when Apple can explain — and justify — iPad's existence amid the pantheon of Apple devices will we see both clarity and growth in the market.