This is an interesting post about how the concept of PageRank for URLs is becoming dated at best, and obsolete at worst.
The idea is that people post in multiple places, and that search engines need to track them across all of them, not just their highly ranked home URL.
So basically, the reputation rank would be on the person, not the URL.
In the novel, everyone walked around with a reputation score hovering above them, which was a combination of all their various contributions to society. And as you did things your score would go up and down.