Yeah, but boards don't really take center stage in Pinterest's UI. Feeds and search results are really an amalgam of various pins and boards.

If I wanted to see a board of "25 Great Christmas Gifts for Under $25", it's not obvious where to look or whose board is authoritative.

Completely agree: Pinterest feels very much to me like a "list" application that is a huge breakout success.

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.

I disagree. What makes a list a list (and not a group of cool shit) is that the list itself has (probably a lot) more value than the individual items. I'd argue the case that this is very rarely true of Pinterest boards, and Pinterest probably would also given the fact that it seems generally as a user you're confronted with a mashup of items from other people's boards, and not as often do you land on the board itself as a curated collection.

Pinterest feels more like visual bookmarking and not lists.

And sometimes, such as content from a poetry focused Pintrest account, a Pintrest board with a list of pictures of words...

Next time you go grocery shopping, use Pinterest for your list . We'll see how long you stick by this statement. :)