we saw another decline last week. now down 75%. no errors.
our decline dates to march 15 also, then april and then last week. a perfect correlation with panda, panda 2.0 and panda 2.2.
my conclusion - somehow the panda test has been mixed into the product search algo as a sitewide trust factor.
ironically, we have seen no reduction in regular organic google referrals - so, our site hasn't been impacted by any of the panda updates, but it has through products only - go figure