The one major idea behind the Lesson is that personal value precedes network value.
What this means is that if we are to build networks of value, then each
person on the network needs to find value for themselves before they
can contribute value to the network. In the case of, people
find value saving their personal bookmarks first and foremost. All
other usage is secondary.

As people use more,
and in order to gain more personal value, they use tags to be able to
find their bookmarks later. Tagging isn’t even the primary function of Most of the tagging done on is done secondarily, and for personal use.

social value of tags on is only a happy side-effect. Even
though most of the ink spilled about is about the social
value, it’s really not the reason why people use it.