It’s telling, in this regard, that the companies most often cited as digital-era successes, Apple and Amazon, both have business models that are firmly rooted in the production and delivery of nonvirtual goods. Apple’s core competency is building better and more beautiful appliances; Amazon’s is delivering everything from appliances to DVDs to diapers more swiftly and cheaply to your door.

By contrast, the more purely digital a company’s product, the fewer jobs it tends to create and the fewer dollars it can earn per user — a reality that journalists have become all too familiar with these last 10 years, and that Facebook’s investors collided with last week. There are exceptions to this rule, but not all that many: even pornography, long one of the Internet’s biggest moneymakers, has become steadily less profitable as amateur sites and videos have proliferated and the “professionals” have lost their monopoly on smut…

A glance at the Bureau of Labor Statistics’ most recent unemployment numbers bears this reality out. Despite nearly two decades of dot-com enthusiasm, the information sector is still quite small relative to other sectors of the economy; it currently has one of the nation’s higher unemployment rates; and it’s one of the few sectors where unemployment has actually risen over the last year.