The trouble with books
Chinese printed works were vast but rare. European books were smaller but still too long. Internet works are the actual length a reader needs, they are (or soon will be) available practically everywhere, and often readers can interact frequently with the author.
Most readers don't want to spend most of their time reading verbose works by single author, when a greater variety of more relevant and thoughtfully concise works are available from a much larger pool of thinkers. Prior to the Internet they had much less choice: books were just the way educated people learned and taught. (And many people still believe that reading and writing books is the sine quo non of being educated, just as many Europeans in 1500 still lauded the superiority of scribal methods and scholastic thought).
Magazines and newspapers involve smaller form factors, but they still draw from a very small pool of authors. These authors can only write in detail about a wider variety of subjects by pretending to know things that they don't: they take human institutions far more complicated than a single human can possibly comprehend and boil them down to a series of hypersimplified theories, what in less authoritative contexts we'd call ideologies or conspiracy theories.
Instead of being forced to read a vast number of words each from a small number and variety of authors, already widely read by many other people (making your reading of them often quite intellectually redundant), on the Internet you can read much less per-author text (and thus, potentially at least, far more thought out per word) from a much greater number and variety of authors.
The Internet also can be more interactive with more select groups than the old face-to-face + snail-mail + books regime— providing much more opportunity for Socratic dialog, glossing, and other intellectual processes that were too often neglected after Gutenberg. And while the Internet can produce far higher amounts of garbage, mixing up thoughtlessly popular haystacks with thoughtfully rare needles, search engines and links often make wading through these vasty spaces much easier. The Internet allows you to meet people who share your specialized interests and dialog with them, making possible specific interactions that rarely happened in the old regime. However, without actually reading the content, i.e. while initially searching for it, it is hard to distinguish thoughtless (even though textual) content from the thoughtful content -- a big reason why at least for the moment book-literacy retains its aura of intellectual superiority over Internet literacy: scholarly publishers with their monetary incentives often take the time to select the most thoughtful works for our consideration. Nevertheless, they lack the knowledge needed to select the most relevant works to match the wide variety of interests and knowledge of their readers, or to judge well among works outside their specialties.
Much as more efficient and speedier transportation networks enabled labor and natural resources to be brought together in a much greater variety of ways, so does the Internet by providing more direct and speedy connections between minds enable a far greater division of knowledge than was possible with in the face-to-face+snail-mail+books regime. However, in contrast to the economy of things, that division of knowledge is largely (so far, at least, and still mostly for the foreseeable future) unmonetized: the information economy is a vastly different beast than the economy of things.
That said, there is a good book(!) that covers much of this (along with of course a bunch of introductory material redundant for most readers, as well as the typical trivial or thoughtless text added to pad it out to books size): Smarter Than You Think by Clive Thompson.
tl;dr if you thought this blog post was too long, why would you ever pick up a book?