Thought I would sign up to post here.
This recent update has hit my website with a cut of over 100,000 unique visitors a day. It literally took a hit of 75-80% or so of Google traffic. All of the popular pages/keywords that ranked, are now the last result for many of those searches (As in last page, last result). I was watching Google Real Time Analytics as the "penalty" or "algorithm" shift took hold. I initially thought it was a server issue. My online visitors dropped from around 800 to 200.
I would say that this is not Penguin. I have done no link building at all. In fact, the website has less than 20-30 or so back links and they are all organic.
Some things to note:
* HTML is valid HTML5.
* Page load times are < 150ms according to WMT.
* Site has a speed ranking of 95. All things done properly, sprites, etc.
* Google crawled (and still crawls) 2-5 pages/second.
* There are no ads/links for cash/etc. (It is a 'passion' project).
* Site is a custom coded application. 15,000 lines... No WordPress blog or similar. Has frequent development.
* Has a bounce rate below 25%.
* Canonical URLs are always used if duplication is possible.
* Widespread use of nofollow/noindex on pages considered not worthy.
* Widespread use of robots.txt
* No real user generated content (where it is, it is blocked from indexing).
* 99% of pages are not even SEO URLs, they use regular extensions.
* Has an average pages per viewer above 10.
* Has two dedicated servers.
* Few thousand registered users.
So, it's probably not Penguin, but is it Panda? Panda was deemed to hit low quality websites. Now I know that it would be easy to jump to the conclusion that anyone who has been hit would consider their website "high quality" and while my site may not be perfect, I at least thought my stats reflected the time I dedicated to this ad-free for fun project. It's a highly functional website.
Still trying to work out where I have gone wrong... It is interesting to note that many of my return visitors were still doing so via Google. This is something that is disappointing with the recent update. It is possible that many of my visitors are not tech-savy, and as such, their reliance on finding my site is via Google rather than directly. This is around 5-8,000 people per day.
I won't sit here and whine that Google has ruined my income, as like I said the project is one for fun and had no ads... But it is still disheartening. The site was approaching 30 page requests a second. I guess one positive is that it will be easier to deploy development updates and maybe even scale back to a single server. Two was a little overkill anyway :)
[edited by: MikeHalo at 12:48 am (utc) on Jun 8, 2013]