Top_Hat - 8:48 am on Jun 10, 2010 (gmt 0)
Just to add my experience to the discussion.
We have a .co.uk shop that has been running for over 10 years, we've never spent much time worrying about seo or google, we've never had a sudden dramatic change in traffic, we just build our pages and sell our products.
Looking at our traffic we had no shift in traffic mayday or throughout may, but on June 1st we lost a huge chunk of traffic coming from google (40% - 50%)
Is that part of mayday or something else?
We also sell our products via amazon uk, we've see a large jump in the number of sales coming from this source (not enough to fill the hole thought)