My first post here...hoping my data can be of some help to us all.
I've got about ten Advanced Web Ranking projects in different industries, each with 10-25 keywords and tracking 5-10 sites. So I'm seeing about 150 keywords and 80 or so sites over a variety of niches. Most of the niches don't appear to be affected other than the normal week to week movement. My e-commerce niche was though, and my site took a massive dive across the board. If we're unable to get back up we'll be out of business. It wasn't only my site. A number of my competitors also lost badly, across the board. A few "new" sites popped in, and a couple of the usual players benefited across the board...more than just rising due to other sites falling.
My e-commerce site is paired with a real physical business at the same physical address (although owned by another family member and a separate company accounting wise). The physical business has been around since the 70's, is featured in tour books, has been on the news, etc. It's a real brand, and our site gets brand searches...probably more so than most of the competition. My family has run and lived off this site for the last 6 years. All of the content is unique and was written by us. All of the pictures are ours, etc. This site is NOT populated by manufacturer descriptions, there is no duplicate content, no low quality text, etc.
I've been reading the theories regarding why sites have taken SERP dives...
Usage Data/Time On Site/Bounce Rate: I have a hard time imagining this could have much to do with anything, as our site has a larger selection, looks as professional and well designed as the other sites that are still ranking...and there's no reason any other site in our niche would have substantially better user data indicators if any.
On Site Content: Our content is all entirely unique. We're probably now above average with the amount of content we have on our site compared to what's currently ranking, but not by a lot. I imagine the "grade level" of our writing would be higher than average. My wife wrote most of it and has a PhD. I can't see how on-site content would have contributed to our massive across the board loss.
Links: My opinion is that this update is related to links. Some Googler, referenced in this thread I believe, stated a few weeks back that something big was coming with the way Google values links. Here's what I'm noticing regarding links and anchor text in THIS NICHE:
The new sites that are now ranking often have very little to zero links to the ranking page. (I know deep pages began ranking a couple months back based on links to the home page/other pages.) While these new sites do have links to the home page, some have zero links with the anchor text that matches the query. For example: if there's a page ranking for "red widgets" there are no links to that page and no links to any other page of the site with the anchor text "red widgets".
Some of these new sites are brands (Walmart, Lowes, etc.). Some of them are older sites with lower quality content. Some of them are new, spammy affiliate sites with terrible content. What they have in common (minus the affiliate sites) is that they have very few links and not much visible on-site or off-site SEO.
Then, there are the usual players who have the greatest number of spammy links. However, the common denominator appears at this point in time to be high PR, obviously paid links. So I'm seeing sites ranking with the greatest number of obviously paid links, and other sites ranking with little to zero links (and/or anchor text links for the given query). It seems to be two opposite ends of the spectrum.
My site does have some paid links. Prior to this "update" you couldn't rank in my niche without having some paid links, regardless of what anyone might like...Google included. If you didn't get paid links of some sort, you didn't rank...simple as that.
The only thing I've discovered that makes our site an outlier is the ratio of unique linking domains to total links. We do some advertising on industry related sites...site wide...which has greatly skewed our ULD to TL ratio. I'm wondering if this could have been the problem.
In any case, if anyone from Google is reading this: High quality sites and businesses have been trashed by this update. People will lose jobs and businesses will close. These businesses are NOT content farms, do not have low quality content, and are most often MORE relevant than the big brands and low quality sites that have replaced them. Please fix this.