Just thought I would jump in and mention that it was EXACTLY June 2nd -June 4th for 3 sites I manage as well. (I manage many, but only these three were affected on this exact date, the others are fine)
Since June 2nd, I have actually shut down 2 of the three sites, due to dismal results and no longer wanting to devote time to a losing venue. The third site is still in place, but running at a loss-rate of 40% year over year.
It is an e-commerce/affiliation website, where we handle actual product sales about 60% of the time and refer buyers to other places they can buy the products we don't stock or drop ship.
ALL foot-traffic loss has been from Google search, roughly 65-70% drop of all Google referrals are simply gone.
- The terms that have dropped have been a mix of long tail, brand, and really just general terms. There is no rhyme or reason behind the drop except that its gone.
- I see a LOT of pogo-sticking of SERP's, with one phrase ranking well today, and nowhere to be found tomorrow. (When I DO check rank, which is not often, its done behind a firefox plugin that proxies my ip and I never click my own results)
- The 3 affected sites were all in the same GWT account, all had adsense from the same account, and were all umbrella'd in the same analytics account as well. I have since created a separate Google services account, and this single site resides there alone.
- The remaining site now ranks for phrases that were dropped from targeting more than 2 years ago! Almost like it was "Reset" to pre-2008. Then tomorrow... it wont rank for those phrases at all!
- SERPS for my previously profitable search phrases are now dominated by spam and mashup sites.
Now for what we have done to it thus far...
- Put it on a dedicated server to make it faster
- Tweaked server caching and spent several days reducing page/image/css/etc sizes.
- We had 2 adsense blocks, they are gone.
- Removed common WMT, Analytics and any other footprint to Google, across ALL websites I am a part of.
I also sent in a reinclusion request to Google, who replied with the canned message after 4 days. (Mid June) Unfortunately, I was a little emotional in the request and it may have hurt my effort, more than it helped.
I had considered going to the Webmaster Forums of Gorg and asking for a public review, but to be honest... I would rather suffer a public stoning.
I have been around web development since building my first site in 1994 and while the Florida update had little to no effect on me, this one is kicking me in the teeth on a few select sites! :-/
I also wear a VERY THICK Google tin-foil-hat and fully believe Google tracks every step I take on the web, associates those steps to my own properties and applies filters based on a profile they keep about me.