It took maybe three years after its quiet launch in 2001 for the Apple iPod to really go mainstream. That's roughly when everyone - not just inveterate music lovers and gadget freaks - knew all about the iconic little music portable.
The iPhone was picked up in slightly shorter time. Early adopters rushed toward the first model, but it was the arrival of the second-gen iPhone 3G two years ago that saw the smartphone's ‘mindshare' skyrocket.
Somehow, I don't think the iPad will have the luxury of such low-key gestation before it's caught full-bore in the searchlamps of worldwide recognition. So there's been enormous pressure to get it right first time.
That pressure is compounded by unease about the entire basis for a ‘new category' product. Is there really a market for such a device? The naysayers mumble about being perfectly satisfied with the current breakdown of personal computing: laptop or desktop PC, and smartphone. They can't see a place for a totable smartslate in their lives. And that's fine.
Because the iPad isn't entirely designed for traditional PC users like you and me. It's aimed at people who've given up on computers that flake out just when you need them to work, expect you to click Start to stop them, lose your files, whirr noisily and produce indecipherable technical gobbledegook.
No, the iPad is not for tech bods inured to the frequent abuse of ‘fatal exception' this and ‘missing dll' that. It's an advanced but intuitive handheld computer for my mum and dad.
But look at netbooks especially, with their cramped displays and fiddly touchpads, from the point of view of an innocent newcomer. Will they mind waiting a minute for it to boot just to check their email? Or put up with slow performance and perplexing settings?
Not to mention security. Watch out which links you click or your Wintel 7 netbook may get infected by something nasty. And security software is likely to slow down bootup still further, and you may get infected anyway, because even the best security software can't be guaranteed to catch every piece of malware.
That third way - an instant-on slate PC that gets stuff done - may be getting a baptism of media fire right now, but that's because its time really has come. And if you can't bring yourself to yield to Apple's pathfinder, don't worry - there will be a slew of me-too rip-offs coming real soon.