The Internet was about information and education, not promotion, because it gave people unprecedented control over the messages to which they were exposed.
It was about earning attention rather than demanding it. It was about dialogue rather and conversation rather than monologue. And it was about multiple stakeholder groups rather than customers alone.
It is the quality of unlimited bandwidth and reader driven choices that makes the Web different from all other media. You have to earn attention on the Web, which makes it peculiarly a PR medium.