Trade magazines can be a barometer of the health of an industry. Journalistically, they cover the health, troubles and trends in an industry. As businesses, they sell advertising to an industry’s suppliers. In a complex symbiotic relationship, trade magazines rely on suppliers to an industry for their own health, while suppliers rely on the business health of the readers of a trade magazine.

When all is in harmony, it’s a virtuous circle. Businesses thrive as the industry’s trade press provides rich information that fuels still more success. This creates demand and interest among still more suppliers, who grow as they find new customers. As the suppliers grow and proliferate, they spend more money on marketing in the trade press, which thrives, and which then provides more information to the market.

Yesterday, Nielsen Business Media reported that Editor & Publisher was shutting down.

Clearly, Nielsen concluded that the supplier community serving the newspaper industry can no longer sustain a media business that reports on the newspaper industry. When you get to the point where the suppliers have dwindled—or not enough of them believe in the value of using a third-party media source for the marketing—you’ve got a problem.

And that tells us a lot about the state of the newspaper industry.

Say what you will about the value of newspapers, and in their heyday—virtually the entire 20th century—they were all powerful. Even now, the journalism produced by newspapers is unmatched. As a force for democracy, and an essential ingredient for a thriving society, newspaper journalism is as vital as ever and lives on—just online.

As a technology, however, it’s all over. Newspapers are dinosaurs. Take the “paper” out of “newspapers.” The world has passed the technology by. What used to be fresh at the doorstep in the morning is now, at best, several hours old. The Web does all the things newspapers used to do, circa 1920, but better, plus a hundred other things too.

This process of transformation is causing enormous disruption and pain. But in its wake come thousands of small entrepreneurial businesses as well as leaner, better old-line newspaper companies that are Internet-centric.

One victim of the transformation is Editor & Publisher, which is a bit ironic, given that E&P itself transformed into an online-centric business several years ago. In recent years it has been an award-winning, game-changing media brand. Just not enough of a business for Nielsen Business Media. But its editor, Greg Mitchell, is well regarded, and what didn’t work for Nielsen perhaps could work for Mitchell in another context.

Great editors, after all, are brands unto themselves.