When it arrived the web seemed to fill all of those niches at once. The web was surprisingly good at emulating a TV, a newspaper, a book, or a radio. Which meant that people expected it to answer the questions of each medium, and with the promise of advertising revenue as incentive, web developers set out to provide those answers. As a result, people in the newspaper industry saw the web as a newspaper. People in TV saw the web as TV, and people in book publishing saw it as a weird kind of potential book. But the web is not just some kind of magic all-absorbing meta-medium. It's its own thing.
A great article. Go read it now.