My good man, we have had information economies since we have had information, and a means - any means - of commoditizing it. :) (There is great argument over what the term "information economy" even means ... my definition is a liberal one.) The only difference between now and the past is the level of independence that types of content have gained from types of containers. We used to only be able to broadcast morse code via wire, and the airwaves were right out. Nowadays we can broadcast damn near anything via wire and airwaves alike, and manage the ways and means it is stored with much more flexibility.
But just because the costs are not apparent at the granular scale doesn't mean that the costs are irrelevant. Consider what total junk the internet would be if we couldn't get electric power (or just couldn't pay for it). Consider the manufacturing costs of the high-end switching equipment that forms the backbone of our networks (and again, who pays for it). Consider how, as the breadth of our information supply increases, exponentially more processing time is required to derive useful results from it. It still is an economy of service and scarcity - it's just got a big bendy electronic joint in the middle, and at one end of that joint you have a bunch of programmers sitting at keyboards ... and among them the occasional fruit loop who thinks he's part of a "post-materialist revolution" on account of how much his job is like the one George Jetson had, where he would just push one button over and over until his finger got sore, and then clock out for the day.
Also, I'd never make the claim that, just because I can duplicate certain bits and bytes indefinitely, the media I have duplicated has no reason to be scarce anymore. In terms of economics, I think the argument should be approached from the other end:
So you can duplicate certain bits and bytes indefinitely. Why would you? What would be your reason for doing that? Are you doing it to keep a backup? That seems wise. Are you doing it to give it to someone else for free? Okay; whatever flips your cookie... Are you doing it for a fee, or so that your friend can avoid a fee? Congratulations, you are participating in an economy of scarcity. In the first instance, you're attempting to enforce one - and in the second, you're attempting to subvert one!
Welcome to the murky for-profit fist-fight of the "new economy", where we encounter such weird edge cases as fake "name brand" bags, patented gene sequences, generic drugs, and boxed copies of Windows XP h4x()r Edition selling for two bucks each, next to the hotdogs on a street vendor's cart. (Ol' Mr. Dibbler will even throw in Madonna's last album for free, and that's cutting his own throat; he swears.)
For what it's worth, I predict that the internet will eventually be paved over by amalgamated content providers, as we all undergo an intimately related transition: Our home computers will be replaced by set-top boxes that browse the web and run iTunes, and are all-too-aware of the latest high tech encryption and DRM schemes. We will pay one cent a month for each AIM account we have, ten cents per minute of video we watch, ten cents per minute of audio we download, and 40 bucks a month just to keep the thing online. And one hundredth of a cent for each google search we invoke.
I suspect these boxes will all be running OS X.
It's not a terrible future, not really ... though it is a significantly less flexible one. And we can pretty much kiss our "post-materialist" Valhalla goodbye. :)