Forget whether or not to put your keyword in it, make it relevant to a searcher and write it for humans, not search engines. If you want to have this 20-word meta description which accurately describes the page you have optimised (for one or two keyword phrases) when people use Google to search, make sure the keyword is in there. There is more likelihood it will be used by Google as your snippet description in SERPs.
Naturally, business owners want to rank for lots of keywords in organic listings with their website. The challenge for webmasters and SEO is that Google doesn’t want business owners to rank for lots of keywords using autogenerated content especially when that produces A LOT of pages on a website using (for instance) a list of keyword variations page-to-page.
QUOTE: “They follow the forms you gather data you do so and so and so forth but they don’t get any laws they don’t haven’t found out anything they haven’t got anywhere yet maybe someday they will but it’s not very well developed but what happens is an even more mundane level we get experts on everything that sound like this sort of scientific expert they they’re not scientist is a typewriter and they make up something.”  Richard Feynman, Physicist

Ask for explanations if something is unclear. If an SEO creates deceptive or misleading content on your behalf, such as doorway pages or "throwaway" domains, your site could be removed entirely from Google's index. Ultimately, you are responsible for the actions of any companies you hire, so it's best to be sure you know exactly how they intend to "help" you. If an SEO has FTP access to your server, they should be willing to explain all the changes they are making to your site.
In December 2009, Google announced it would be using the web search history of all its users in order to populate search results.[33] On June 8, 2010 a new web indexing system called Google Caffeine was announced. Designed to allow users to find news results, forum posts and other content much sooner after publishing than before, Google caffeine was a change to the way Google updated its index in order to make things show up quicker on Google than before. According to Carrie Grimes, the software engineer who announced Caffeine for Google, "Caffeine provides 50 percent fresher results for web searches than our last index..."[34] Google Instant, real-time-search, was introduced in late 2010 in an attempt to make search results more timely and relevant. Historically site administrators have spent months or even years optimizing a website to increase search rankings. With the growth in popularity of social media sites and blogs the leading engines made changes to their algorithms to allow fresh content to rank quickly within the search results.[35]
Users will occasionally come to a page that doesn't exist on your site, either by following a broken link or typing in the wrong URL. Having a custom 404 page30 that kindly guides users back to a working page on your site can greatly improve a user's experience. Your 404 page should probably have a link back to your root page and could also provide links to popular or related content on your site. You can use Google Search Console to find the sources of URLs causing "not found" errors31.
QUOTE: “Search engine optimization is often about making small modifications to parts of your website. When viewed individually, these changes might seem like incremental improvements, but when combined with other optimizations, they could have a noticeable impact on your site’s user experience and performance in organic search results.” Google Starter Guide, 2008
You should build a website to benefit your users, and any optimization should be geared toward making the user experience better. One of those users is a search engine, which helps other users discover your content. Search Engine Optimization is about helping search engines understand and present content. Your site may be smaller or larger than our example site and offer vastly different content, but the optimization topics we discuss below should apply to sites of all sizes and types. We hope our guide gives you some fresh ideas on how to improve your website, and we'd love to hear your questions, feedback, and success stories in the Google Webmaster Help Forum1.
TASK – If running a blog, first, clean it up. To avoid creating pages that might be considered thin content in 6 months, consider planning a wider content strategy. If you publish 30 ‘thinner’ pages about various aspects of a topic, you can then fold all this together in a single topic page centred page helping a user to understand something related to what you sell.
Domain authority is an important ranking phenomenon in Google. Nobody knows exactly how Google calculates, ranks and rates the popularity, reputation, intent or trust of a website, outside of Google, but when I write about domain authority I am generally thinking of sites that are popular, reputable and trusted – all of which can be faked, of course.
******” Quote from Google: One other specific piece of guidance we’ve offered is that low-quality content on some parts of a website can impact the whole site’s rankings, and thus removing low-quality pages, merging or improving the content of individual shallow pages into more useful pages, or moving low-quality pages to a different domain could eventually help the rankings of your higher-quality content. GOOGLE ******
QUOTE: “In place of a pop-up try a full-screen inline ad. It offers the same amount of screen real estate as pop-ups without covering up any content. Fixing the problem depends on the issue you have for example if it’s a pop-up you’ll need to remove all the pop-up ads from your site but if the issue is high ad density on a page you’ll need to reduce the number of ads” Google, 2017
SEO may generate an adequate return on investment. However, search engines are not paid for organic search traffic, their algorithms change, and there are no guarantees of continued referrals. Due to this lack of guarantees and certainty, a business that relies heavily on search engine traffic can suffer major losses if the search engines stop sending visitors.[61] Search engines can change their algorithms, impacting a website's placement, possibly resulting in a serious loss of traffic. According to Google's CEO, Eric Schmidt, in 2010, Google made over 500 algorithm changes – almost 1.5 per day.[62] It is considered a wise business practice for website operators to liberate themselves from dependence on search engine traffic.[63] In addition to accessibility in terms of web crawlers (addressed above), user web accessibility has become increasingly important for SEO.
QUOTE:  Each piece of duplication in your on-page SEO strategy is ***at best*** wasted opportunity. Worse yet, if you are aggressive with aligning your on page heading, your page title, and your internal + external link anchor text the page becomes more likely to get filtered out of the search results (which is quite common in some aggressive spaces). Aaron Wall, 2009
A poor 404 page and user interaction with it, can only lead to a ‘poor user experience’ signal at Google’s end, for a number of reasons. I will highlight a poor 404 page in my audits and actually programmatically look for signs of this issue when I scan a site. I don’t know if Google looks at your site that way to rate it e.g. algorithmically determines if you have a good 404 page – or if it is a UX factor, something to be taken into consideration further down the line – or purely to get you thinking about 404 pages (in general) to help prevent Google wasting resources indexing crud pages and presenting poor results to searchers. I think rather that any rating would be a second order scoring including data from user activity on the SERPs – stuff we as SEO can’t see.
He is the co-founder of NP Digital. The Wall Street Journal calls him a top influencer on the web, Forbes says he is one of the top 10 marketers, and Entrepreneur Magazine says he created one of the 100 most brilliant companies. Neil is a New York Times bestselling author and was recognized as a top 100 entrepreneur under the age of 30 by President Obama and a top 100 entrepreneur under the age of 35 by the United Nations.