Only in the last 50 pages, when he appraises the excesses of the modern internet — which mutely scrapes our data and stalks us with weight-loss ads; which narcotizes us with listicles and hands to preening no-talents their own micro-platforms on which to strut their micro-stuff — does Mr. Wu turn savage, sinking enough venom into Twitter and Instagram to kill a baby monkey: “Fame, or the hunger for it, would become something of a pandemic, swallowing up more and more people and leaving them with scars of chronic attention-whoredom.”

But because “The Attention Merchants” is comprehensive and conscientious, readers are bound to stumble on ideas and episodes of media history that they knew little about. Mr. Wu, the author of “The Master Switch,” writes with elegance and clarity, giving readers the pleasing sensation of walking into a stupendously well-organized closet. As a lawyer and star professor at Columbia Law School — he famously coined the term “net neutrality” — he is clearly in the habit of laying out his arguments in logical, progressive steps.

Throughout his book, Mr. Wu explores “the fundamental, continual dilemma for the attention merchant — just how far will he go to get his harvest?” Almost inevitably, these merchants run afoul of our core sense of privacy. But over time, that sense has eroded.

By the end of the 1920s, most Americans were accustomed to being “cajoled and sold to” in print and on billboards. By the end of the 1950s, advertisers had wormed their way into the family living room, with television and radio networks “owning” times of the day that were previously sacred, like dinner hour. Then came the personal computer, the internet and, finally, the “fourth screen”: our mobile phones. They devoured every morsel of attention we had left, “rather in the way fracking would later recover great reserves of oil once considered wholly inaccessible.”

Mr. Wu’s chapters about the early days of advertising are some of this book’s most enjoyable, easily serving as a reader’s companion to “Mad Men.” (They contain great product trivia, too: Listerine was once marketed as a floor cleaner.) But it’s the last third of “The Attention Merchants,” in which Mr. Wu charts the rise and fall of the utopian internet, that is truly memorable.