With the new Kindle Fire rolling out the door, I'm suddenly having a major flashback to the nineties.

Remember when it seemed like every company in the known universe was fighting to get a set-top box into the home? Remember all the hype about how our TVs were going to turn into Internet portals and become live shopping systems? How did that work out for us?

Things don't usually turn out the way we expect--who would have expected that a company like Amazon.com would create the set-top box of the future? It's called the Kindle Fire HD.

And yet for a time, everyone took this set-top box idea oh-so-seriously. Not least of all because the TV and the set-top box were seen as the ways to get the attention of ordinary consumers who still found computing intimidating. The other idea behind a set-top box wasn't just to give consumers a convenient walled garden to play in, but to allow content providers another managed pipeline into the home. Movies and TV on demand, video games delivered straight over the wire, video chat -- does all this sound vaguely familiar? It should.

Hence devices such as WebTV a.k.a MSN TV, and for proof of its intentions look no further than the words of its co-creator, Steve Perlman: "I've been working to create an interactive television my entire life. I always knew it was a way of bringing computers to average people." But MSN TV almost didn't make it out of the gate--a harbinger of how successful set-top boxes would be generally.

In fact, it's hard to bring to mind a single set-top box--apart from the humdrum models built specifically for cable companies--that survived long enough to deliver on its promises. Apple's Pippin, for instance, which couldn't decide if it was a set-top box or a game console, was overpriced, and was terrible anyway.

Individual limits of WebTV and Pippin and so forth aside, those boxes all fell into the same general bucket of failure. They were too closed-ended, without a major culture of software to make them useful, and most of what people would have done with them was being shifted to the increasingly user-friendly PC anyway.

But their ultimate limitation was the big box underneath them: the TV. Not just because the resolution of an NTSC TV made anything beyond the most rudimentary Web browsing a painful experience, but because the TV made for a giant boat anchor just itching to be dumped overboard. Before the 2000s were out, everything we did with our TVs, and our TVs themselves, was to undergo a grand mutation of its own that would make the idea of the set-top box doubly useless.

Enter the smartphone, and its larger cousin the tablet. As Wi-Fi, high-speed data plans, and on-line content delivery took off, almost everything that would have been done through a set-top box in the first place--or which had moved to the PC--was now moving into one's pocket. People were willing to give up a little audio quality for the sake of having a thousand-plus albums on the go; they were also willing to give up a little picture quality and screen size for the same convenience in video. And in the case of a tablet like the iPad with the Retina Display, they gave up very little, if anything.

The other thing that set-top boxes failed to create--a consistent ecosystem for content--is something smartphones and tablets have delivered to us in spades. iOS and Android for most people; Windows 8 (and Windows 8 RT) bringing up the rear; and others waiting in the wings for their turn, I'm sure. These devices provided far richer software platforms to work with--and over a decade of technological progress didn't hurt, either, allowing everything from 8-megapixel cameras to GPS sensors to be crammed into a space anywhere from the size of a bar of soap to a large paperback.

The Kindle Fire HD in particular brings set-top boxes back to mind all the more, because it's clearly Amazon's next iteration of a hardware portal for its content domain. If the Kindle Fire HD is the set-top box, Amazon is the cable company--all one channel, but one where you can order up just about anything, from digital books to seasons of TV. It makes the aspirations of movies-on-demand and the Home Shopping Network seem downright tame in comparison. It does away not only with the set-top box, but the set itself.

Amazon did what the other set-top box makers couldn't, because it was out of their league. Instead of starting with the hardware cart, they created the ecosystem horse first. They built the whole Amazon mall store, then added a new side entrance with its own valet parking. You can still use Amazon through any number of devices--yes, even the hoary old desktop and Web browser. That's why even if the Kindle Fire HD or any of its successors come a cropper, Amazon still wins. They've built something bigger than any one gizmo can ever hold.