Heh, careful with that "we" - don't leave out those of us who are in the target demographic of both Hacker News and Pinterest. :)
I have less purchasing intent while browsing Pinterest than I do while looking at Yelp or Amazon (or Etsy), but I spend more time on Pinterest than on shopping sites. I've bought several things I had originally pinned just because they were interesting and then later realized would make a good gift for somebody.