I do also wonder how much Pinterest use is more passive even than Twitter. Sure, there are lots of Twitter bots and lurkers, but everyone I know on Pinterest complains that they get into an unusable state where they just keep "pinning" things from badges all over the web, but have too much junk pinned to manage/reference/use.
I use Pinterest (http://www.pinterest.com/anthonycreek/), but I'm quite selective of what I pin so I can easily see and appreciate everything on my boards. I also only have a handful of boards.
I see people with dozens of boards and thousands (even tens of thousands) of pins. I don't know what the point of that is unless you are trying to simply grow your following by being everywhere.
