I would replace scarcity of knowledge with scarcity of information/media in general and expand this to the entire media industry.

For years television companies paid top dollar for content so that they could create crowds for their advertisers. Because there were very few people capable of even reaching a large crowd (ie: there were large distribution barriers), there was, relative to now, a scarcity of media in this arena.

Provided you got the right distribution, it didn't really matter what you put out there because there were so few people capable of operating at scale (again this goes for all industries, from Hollywood to journos). I did a lot of consulting for Time Warner about 2 years ago, and one of the things I heard their executives say over and over again was "We think there will always be a market for our premium content." They fundamentally failed to understand their business model: they thought it was providing high quality content to build crowds for advertisers, while in fact it had nothing to do with the content (the content was just the means, not the ends). In this sense Google is their prime competition (same ends, far cheaper means), and is absolutely eating their lunch.

The other thing they didn't understand is that people simply don't have the hours in the day anymore. If 10 years ago you watched 10 hours of television a week, it's likely you now spend some portion of that on Facebook, youtube, blogs or some other media outlet that we consider "user generated." This hurt television more than the industry thought it would, again, due to the the fact that they were winning in distribution much more than quality, like they thought, and because as advertising approaches a zero-sum game linearly, the prices grow exponentially. Now that it is easier to capture the long tail cheaply, and to more directly target consumers, what traditional media companies have offered (the distribution mechanism) is no longer valuable. As a content filter, the publishing houses have always been crap, they just didn't know it.

The industry optimized years ago for this inability to hit the long tail: the information provided is extremely abstracted in order to provide mass appeal. Taking NYTimes as an example, general news source dominance led them again to optimize for what they THOUGHT was quality winning: they hired the best journos they could find, instead of industry experts with writing skills. When blogs allowed these industry experts to easily distribute their own work, the middle man was removed. Now these companies are so big and have optimized everything from their recruiting processes to their syndication for this model: high quality journos, high quality content. They are too big, and it's become very difficult for them to pivot.

This phenomenon is easily transferrable to almost all media industries, and is the general "cheapening" (I would call market-readjustment) of the value of media. It turns out people have more specific taste than the media industry gave them credit for (or was able to serve), and now that these specific tastes are easily served, the general, abstracted versions of these media have lost tremendous value.

Hope that makes sense, /rant.