Google is indexing billions of sites. If Google is 99% perfect (and it is not) there would still be millions of spam sites sneaking into the rankings. Spam sites are a good learning opportunity for smart webmasters to figure out what is powering Google's secret algo. Learn from them & then figure out if the risk/reward ratio makes sense for you (it probably doesn't). Don't blindly follow the spam sites. A smart spammer knows they are living on borrowed time. Eventually, a spam site will be penalized or banned by Google. The hope is to make enough money before Google catches up to you.

The latest round of spam sites are becoming more sophisticated with much more to learn about. You can potentially adjust/adapt some of these tactics and strategies to benefit clean vanilla sites. Don't get angry since that doesn't generate profit. Focus on addressing these sites in a more productive manner.

What I noticed is in my vertical and keywords that I monitor. Google turned up a notch a brand signal (major brands) while lowering the benefit of mid pack domains that may be more relevant. So the mix I noticed before and after the recent volatility is something like this

Before:
4 relevant domains + 6 strong brands

Now:
6~7 strong brands + 2 relevant domains + 1~2 obvious spams. I am seeing poor content from brands that are far more inferior to the relevant domains.

Add the mix of sometimes stupid title rewrites, some people (non brands but relevant domains) will see disastrous results. On the other end, if your domain is the relevant 2 survived from the "before" 4, you will see massive gains. Google Roulette is what it is.

Of course spam sites live on borrowed times, that's why it's all machine generated that makes thousands of them on the spot. As long as Google does not give enough weight to relevance but rely on other brand related signals, that will always be a part of the game.

Opportunity? Sure.
Luck? You bet.
Sure Bet? Become brands that push millions in ad spend, or join the dark side and become spammers.

ps. I joined brands. SEO is much easier with millions in ad spend.

It's also possible that your definition of a spam site is different from Google's (or users, for that matter). Many coupon sites, for example, have what may look like pretty thin content with mostly affiliate links, but if it gets users their discount then it's mission accomplished.

You would think Google would hire raters that go around and do searches and then rate pages (which ultimately would flag the website) on how spammy it is. This mainly would include quality of content since the algo has huger problems in determining this. This rating wouldn't be really counted in the algo until at least 10 people had performed ratings. These raters could also concentrate more on the common search terms and maybe the first couple of pages of the serps. This way the spam should slowly get pushed down as more and more raters voice their opinion.

I know Google does something like this already (I believe I have read it somewhere) but they really either need to hire more people or increase the ranking signal of the raters.

As others have said Google has there own determination of what is spam. IMO Google Discover results on my phone is full of spammy articles. This is mainly do to the large amounts of ads in articles these days including video ones that autorun. The amount of ads should be cut in half IMO and video ads on mobile data should not be allowed but obviously Google things this is okay or they do not, but don't want to rock the boat and start penalizing websites who will then complain about Google in the media (who has troubles with the FTC already).

You would think Google would hire raters that go around and do searches and then rate pages (which ultimately would flag the website) on how spammy it is. ...I know Google does something like this already...

Sort of. The job of the search quality raters is to test changes to the SERPs in a non-live environment.

But it's not to go around policing the SERPs and flagging poor results.

By the time the SERPs are live machine learning takes over and can flag poor performing SERPs and identify what went wrong.

That said, I think the SERPs have been a little hairy lately, like waves of poor results as they seemingly release something new and then the wave pulls back and it gets less hairy.

Well Google maybe should have the raters affect the SERPS to a certain degree. Google's AI is extremely poor at determining what is quality content. It cannot understand what is written and only uses signals to decide rankings.

Well Google maybe should have the raters affect the SERPS to a certain degree.

Again, this is not what the raters do. They rate algorithms via double-blind samples of search results and tests. Raters in fact do not directly affect rankings at all.

By down-rating an algorithm that allows a lot of spam sites to rank well, though, raters might indirectly be down ranking spam as well, but it's not a a question of a rater downranking a specific spam site. Such a system could never scale, and would be much too slow to react, say, to push-button spam.

There is, btw, a several page section in the last raters guidelines I checked out about spam as described by the guidelines (and described pretty well, I think)... , and spam sites do get the lowest of the low quality scores.

I should mention that there is a team of human "reviewers"... not quality raters... who do check out and review spam sites directly, and that is the Spam Team. Google allows multiple ways for its users to report spam... and the spam team is purported to have great insight into individual sites remotely. Again, that's for identifying spam... not for ranking billions of pages on a competitve basis.

Much spam relies hijacking of sites or domains... which involves the exploitation of vulnerabilities often caused by poor site maintenace and unpatched code. As Matt Cutts used to discuss at length, Google cannot patch the vulnerabilites in code for webmasters. Webmasters have got to do that on their own.

One further thought.... If raters could directly affect the rankings of a site, that would open up the system to a lot a problems. Can you imagine the outcry, say, if it was determined that a particular rater could make a site go up or down in the serps?