Google has a LONG list of technical requirements it advises you meet, on top of all the things it tells you NOT to do to optimise your website. Meeting Google’s technical guidelines is no magic bullet to success – but failing to meet them can impact your rankings in the long run – and the odd technical issue can actually severely impact your entire site if rolled out across multiple pages.
When you write a page title, you have a chance right at the beginning of the page to tell Google (and other search engines) if this is a spam site or a quality site – such as – have you repeated the keyword four times or only once? I think title tags, like everything else, should probably be as simple as possible, with the keyword once and perhaps a related term if possible.
Sometimes I think if your titles are spammy, your keywords are spammy, and your meta description is spammy, Google might stop right there – even they probably will want to save bandwidth at some time. Putting a keyword in the description won’t take a crap site to number 1 or raise you 50 spots in a competitive niche – so why optimise for a search engine when you can optimise for a human? – I think that is much more valuable, especially if you are in the mix already – that is – on page one for your keyword.
QUOTE: “The score is determined from quantities indicating user actions of seeking out and preferring particular sites and the resources found in particular sites. *****A site quality score for a particular site**** can be determined by computing a ratio of a numerator that represents user interest in the site as reflected in user queries directed to the site and a denominator that represents user interest in the resources found in the site as responses to queries of all kinds The site quality score for a site can be used as a signal to rank resources, or to rank search results that identify resources, that are found in one site relative to resources found in another site.” Navneet Panda, Google Patent
It’s important to note that Google is responsible for the majority of the search engine traffic in the world. This may vary from one industry to another, but it’s likely that Google is the dominant player in the search results that your business or website would want to show up in, but the best practices outlined in this guide will help you to position your site and its content to rank in other search engines, as well.

Important: The Lowest rating is appropriate if all or almost all of the MC on the page is copied with little or no time, effort, expertise, manual curation, or added value for users. Such pages should be rated Lowest, even if the page assigns credit for the content to another source. Important: The Lowest rating is appropriate if all or almost all of the MC on the page is copied with little or no time, effort, expertise, manual curation, or added value for users. Such pages should be rated Lowest, even if the page assigns credit for the content to another source.

On October 17, 2002, SearchKing filed suit in the United States District Court, Western District of Oklahoma, against the search engine Google. SearchKing's claim was that Google's tactics to prevent spamdexing constituted a tortious interference with contractual relations. On May 27, 2003, the court granted Google's motion to dismiss the complaint because SearchKing "failed to state a claim upon which relief may be granted."[68][69]
In March 2006, KinderStart filed a lawsuit against Google over search engine rankings. KinderStart's website was removed from Google's index prior to the lawsuit, and the amount of traffic to the site dropped by 70%. On March 16, 2007, the United States District Court for the Northern District of California (San Jose Division) dismissed KinderStart's complaint without leave to amend, and partially granted Google's motion for Rule 11 sanctions against KinderStart's attorney, requiring him to pay part of Google's legal expenses.[70][71]
And so on and so on. The point of this step isn't to come up with your final list of keyword phrases. You just want to end up with a brain dump of phrases you think potential customers might use to search for content related to that particular topic bucket. We'll narrow the lists down later in the process so you don't have something too unwieldy. Once you have your final list, there are several data-driven tools available to you for finding out which keywords you're most likely to rank well for. 
If Google finds two identical pieces of content, whether on your own site, or on another you’re not even aware of, it will only index one of those pages. You should be aware of scraper sites, stealing your content automatically and republishing as your own. Here’s Graham Charlton’s thorough investigation on what to if your content ends up working better for somebody else.
The above information does not need to feature on every page, more on a clearly accessible page. However – with Google Quality Raters rating web pages on quality based on Expertise, Authority and Trust (see my recent making high-quality websites post) – ANY signal you can send to an algorithm or human reviewer’s eyes that you are a legitimate business is probably a sensible move at this time (if you have nothing to hide, of course).
QUOTE: “So there’s three things that you really want to do well if you want to be the world’s best search engine you want to crawl the web comprehensively and deeply you want to index those pages and then you want to rank or serve those pages and return the most relevant ones first….. we basically take PageRank as the primary determinant and the more PageRank you have that is the more people who link to you and the more reputable those people are the more likely it is we’re going to discover your page…. we use page rank as well as over 200 other factors in our rankings to try to say okay maybe this document is really authoritative it has a lot of reputation because it has a lot of PageRank … and that’s kind of the secret sauce trying to figure out a way to combine those 200 different ranking signals in order to find the most relevant document.” Matt Cutts, Google
Many blogging software packages automatically nofollow user comments, but those that don't can most likely be manually edited to do this. This advice also goes for other areas of your site that may involve user-generated content, such as guest books, forums, shout-boards, referrer listings, etc. If you're willing to vouch for links added by third parties (for example, if a commenter is trusted on your site), then there's no need to use nofollow on links; however, linking to sites that Google considers spammy can affect the reputation of your own site. The Webmaster Help Center has more tips on avoiding comment spam40, for example by using CAPTCHAs and turning on comment moderation.

The reality in 2019 is that if Google classifies your duplicate content as THIN content, or MANIPULATIVE BOILER-PLATE or NEAR DUPLICATE ‘SPUN’ content, then you probably DO have a severe problem that violates Google’s website performance recommendations and this ‘violation’ will need ‘cleaned’ up – if – of course – you intend to rank high in Google.
Understanding the balance of terms that might be a little more difficult due to competition, versus those terms that are a little more realistic, will help you maintain a similar balance that the mix of long-tail and head terms allows. Remember, the goal is to end up with a list of keywords that provide some quick wins but also helps you make progress toward bigger, more challenging SEO goals.
If you own, manage, monetize, or promote online content via Google Search, this guide is meant for you. You might be the owner of a growing and thriving business, the webmaster of a dozen sites, the SEO specialist in a Web agency or a DIY SEO ninja passionate about the mechanics of Search : this guide is meant for you. If you're interested in having a complete overview of the basics of SEO according to our best practices, you are indeed in the right place. This guide won't provide any secrets that'll automatically rank your site first in Google (sorry!), but following the best practices outlined below will hopefully make it easier for search engines to crawl, index and understand your content.