Google engineers are building an AI – but it’s all based on simple human desires to make something happen or indeed to prevent something. You can work with Google engineers or against them. Engineers need to make money for Google but unfortunately for them, they need to make the best search engine in the world for us humans as part of the deal. Build a site that takes advantage of this. What is a Google engineer trying to do with an algorithm? I always remember it was an idea first before it was an algorithm. What was that idea? Think “like” a Google search engineer when making a website and give Google what it wants. What is Google trying to give its users? Align with that. What does Google not want to give its users? Don’t look anything like that. THINK LIKE A GOOGLE ENGINEER & BUILD A SITE THEY WANT TO GIVE TOP RANKINGS.
Another example when the “nofollow" attribute can come handy are widget links. If you are using a third party's widget to enrich the experience of your site and engage users, check if it contains any links that you did not intend to place on your site along with the widget. Some widgets may add links to your site which are not your editorial choice and contain anchor text that you as a webmaster may not control. If removing such unwanted links from the widget is not possible, you can always disable them with “nofollow" attribute. If you create a widget for functionality or content that you provide, make sure to include the nofollow on links in the default code snippet.
At the moment, I don’t know you, your business, your website, your resources, your competition or your product. Even with all that knowledge, calculating ROI is extremely difficult because ultimately Google decides on who ranks where in its results – sometimes that’s ranking better sites, and sometimes (often) it is ranking sites breaking the rules above yours.

Either porn SC or Ads containing porn on non­Porn pages can be very distracting or even upsetting to users. Please refresh the page a few times to see the range of Ads that appear, and use your knowledge of the locale and cultural sensitivities to make your rating. For example, an ad for a model in a revealing bikini is probably acceptable on a site that sells bathing suits. However, an extremely graphic porn ad may warrant a Low (or even Lowest) rating.” Google Search Quality Evaluator Guidelines 2017

QUOTE: “Anytime you do a bigger change on your website if you redirect a lot of URLs or if you go from one domain to another or if you change your site’s structure then all of that does take time for things to settle down so we can follow that pretty quickly we can definitely forward the signals there but that doesn’t mean that’ll happen from one day to next” John Mueller, Google 2016
Make it as easy as possible for users to go from general content to the more specific content they want on your site. Add navigation pages when it makes sense and effectively work these into your internal link structure. Make sure all of the pages on your site are reachable through links, and that they don't require an internal "search" functionality to be found. Link to related pages, where appropriate, to allow users to discover similar content.
It is important you spread all that real ‘PageRank’ – or link equity – to your sales keyword / phrase rich sales pages, and as much remains to the rest of the site pages, so Google does not ‘demote’ pages into oblivion –  or ‘supplemental results’ as we old timers knew them back in the day. Again – this is slightly old school – but it gets me by, even today.
QUOTE: “Google Webmaster Tools notice of detected doorway pages on xxxxxxxx – Dear site owner or webmaster of xxxxxxxx, We’ve detected that some of your site’s pages may be using techniques that are outside Google’s Webmaster Guidelines. Specifically, your site may have what we consider to be doorway pages – groups of “cookie cutter” or low-quality pages. Such pages are often of low value to users and are often optimized for single words or phrases in order to channel users to a single location. We believe that doorway pages typically create a frustrating user experience, and we encourage you to correct or remove any pages that violate our quality guidelines. Once you’ve made these changes, please submit your site for reconsideration in Google’s search results. If you have any questions about how to resolve this issue, please see our Webmaster Help Forum for support.” Google Search Quality Team, 2011
As of October 2018 almost 4.2 billion people were active internet users and 3.4 billion were social media users (Statista). China, India and the United States rank ahead all other countries in terms of internet users. This gives a marketer an unprecedented number of customers to reach with product and service offerings, available 24 hours a day, seven days a week. The interactive nature of the internet facilitates immediate communication between businesses and consumers, allowing businesses to respond quickly to the needs of consumers and changes in the marketplace. "Everyone has the internet in their pocket all the time, and this changes everything for small businesses" (Cory Capoccia, Forbes).
You may not want certain pages of your site crawled because they might not be useful to users if found in a search engine's search results. If you do want to prevent search engines from crawling your pages, Google Search Console has a friendly robots.txt generator to help you create this file. Note that if your site uses subdomains and you wish to have certain pages not crawled on a particular subdomain, you'll have to create a separate robots.txt file for that subdomain. For more information on robots.txt, we suggest this Webmaster Help Center guide on using robots.txt files13.
QUOTE: “Starting April 21 (2015), we will be expanding our use of mobile-friendliness as a ranking signal. This change will affect mobile searches in all languages worldwide and will have a significant impact in our search results. Consequently, users will find it easier to get relevant, high-quality search results that are optimized for their devices”. GOOGLE

It's important to check that you have a mix of head terms and long-tail terms because it'll give you a keyword strategy that's well balanced with long-term goals and short-term wins. That's because head terms are generally searched more frequently, making them often (not always, but often) much more competitive and harder to rank for than long-tail terms. Think about it: Without even looking up search volume or difficulty, which of the following terms do you think would be harder to rank for?
There are a lot of definitions of SEO (spelled Search engine optimisation in the UK, Australia and New Zealand, or search engine optimization in the United States and Canada) but organic SEO in 2020 is still mostly about getting free traffic from Google, the most popular search engine in the world (and almost the only game in town in the UK in 2020):
If you link out to irrelevant sites, Google may ignore the page, too – but again, it depends on the site in question. Who you link to, or HOW you link to, REALLY DOES MATTER – I expect Google to use your linking practices as a potential means by which to classify your site. Affiliate sites, for example, don’t do well in Google these days without some good quality backlinks and higher quality pages.
QUOTE: “Supplementary Content contributes to a good user experience on the page, but does not directly help the page achieve it purpose. SC is controlled by webmasters and is an important part of the user experience. One common type of SC is navigation links that allow users to visit other parts of the website. Note that in some cases, content behind tabs may be considered part of the SC of the page. Sometimes the easiest way to identify SC is to look for the parts of the page that are not MC or Ads. ” Google Search Quality Evaluator Guidelines 2019
While you can often start with a keyword and create a piece of content around that term, sometimes your content already exists, and you need to figure out how to match it to keywords. To do this, create what's known as a "content to keyword map." Creating this map can help you understand the impact of your existing content and identify weak links or gaps that need filling.

This helpful tool scans your backlink profile and turns up a list of contact information for the links and domains you'll need to reach out to for removal. Alternatively, the tool also allows you to export the list if you wish to disavow them using Google's tool. (Essentially, this tool tells Google not to take these links into account when crawling your site.)
Inclusion in Google's search results is free and easy; you don't even need to submit your site to Google. Google is a fully automated search engine that uses web crawlers to explore the web constantly, looking for sites to add to our index. In fact, the vast majority of sites listed in our results aren't manually submitted for inclusion, but found and added automatically when we crawl the web. Learn how Google discovers, crawls, and serves web pages.3