I'd propose most successful social sites are successful list-based services, although the default filtering/ordering is not by author, which seems to be the spe

I'd propose most successful social sites are successful list-based services, although the default filtering/ordering is not by author, which seems to be the specific case that the article contemplates. HN, for example, allows me to go see a list of things that a majority of people in my demographic think is interesting today. Reddit, as one example of a topical social site, takes it a step further and allows users to choose their "vertical," as the author would likely state it.