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.
******” 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 ******
The higher the search volume for a given keyword or keyword phrase, the more work is typically required to achieve higher rankings. This is often referred to as keyword difficulty and occasionally incorporates SERP features; for example, if many SERP features (like featured snippets, knowledge graph, carousels, etc) are clogging up a keyword’s result page, difficulty will increase. Big brands often take up the top 10 results for high-volume keywords, so if you’re just starting out on the web and going after the same keywords, the uphill battle for ranking can take years of effort.
A lot of optimisation techniques that are in the short term effective at boosting a site’s position in Google are against Google’s guidelines. For example, many links that may have once promoted you to the top of Google, may, in fact, today be hurting your site and its ability to rank high in Google. Keyword stuffing might be holding your page back. You must be smart, and cautious, when it comes to building links to your site in a manner that Google *hopefully* won’t have too much trouble with, in the FUTURE. Because they will punish you in the future.

Robots.txt is not an appropriate or effective way of blocking sensitive or confidential material. It only instructs well-behaved crawlers that the pages are not for them, but it does not prevent your server from delivering those pages to a browser that requests them. One reason is that search engines could still reference the URLs you block (showing just the URL, no title or snippet) if there happen to be links to those URLs somewhere on the Internet (like referrer logs). Also, non-compliant or rogue search engines that don't acknowledge the Robots Exclusion Standard could disobey the instructions of your robots.txt. Finally, a curious user could examine the directories or subdirectories in your robots.txt file and guess the URL of the content that you don't want seen.

QUOTE: “How do I move from one domain to another domain and try to preserve the rankings as best as possible?…do a 301 permanent redirect to the new location (assuming that you’re you’re moving for all time and eternity so this is the good case for a permanent or 301 redirect if you were planning to undo this later or it’s temporary then you’d use a 302 redirect)…. search engines should be able to follow the trail of all the 301 redirects” Matt Cutts, Google

Smartphone - In this document, "mobile" or “mobile devices" refers to smartphones, such as devices running Android, iPhone, or Windows Phone. Mobile browsers are similar to desktop browsers in that they can render a broad set of the HTML5 specification, although their screen size is smaller and in almost all cases their default orientation is vertical.

While Google is on record as stating these quality raters do not directly influence where you rank (without more senior analysts making a call on the quality of your website, I presume?) – there are some things in this document, mostly of a user experience nature (UX) that all search engine optimisers and Webmasters of any kind should note going forward.
At first glance, the Ads or SC appear to be MC. Some users may interact with Ads or SC, believing that the Ads or SC is the MC.Ads appear to be SC (links) where the user would expect that clicking the link will take them to another page within the same website, but actually take them to a different website. Some users may feel surprised or confused when clicking SC or links that go to a page on a completely different website.
Consider the length of your typical customer buying cycle. If your products and services have a short customer buying cycle, meaning your customers know what they want, search for it, and buy it, you may benefit from SEM ads that put your product right where customers will see it. Longer buying cycles, where customers research and compare for weeks or months, may not perform as well with SEM, as there isn’t an immediate buy after seeing one ad.
A satisfying UX is can help your rankings, with second-order factors taken into consideration. A poor UX can seriously impact your human-reviewed rating, at least. Google’s punishing algorithms probably class pages as something akin to a poor UX if they meet certain detectable criteria e.g. lack of reputation or old-school SEO stuff like keyword stuffing a site.
to avoid throwing link equity away, you might create HIGH-LEVEL IN-DEPTH TOPIC PAGES on your site and redirect (or use canonical redirects) any related expired content that HAVE INCOMING BACKLINKS, to this topic page (and keep it updated, folding content from old pages, where relevant and there is traffic opportunity, to create TOPIC pages that are focused on the customer e.g. information pages)
For instance, in a recent test (2019), if you have a page title longer than 12 words, all the keywords beyond 12 words evaporated from the page copy. This is a change from the way Google used to work, when the extra words were included as part of the page copy, not just part of the title. So, if you have a 15 word title, the last 3 words will not count towards ranking, if that test result was to be replicated.
This broken-link checker makes it easy for a publisher or editor to make corrections before a page is live. Think about a site like Wikipedia, for example. The Wikipedia page for the term "marketing" contains a whopping 711 links. Not only was Check My Links able to detect this number in a matter of seconds, but it also found (and highlighted) seven broken links.
Use the Keyword Planner to flag any terms on your list that have way too little (or way too much) search volume, and don't help you maintain a healthy mix like we talked about above. But before you delete anything, check out their trend history and projections in Google Trends. You can see whether, say, some low-volume terms might actually be something you should invest in now -- and reap the benefits for later.
Link building is not JUST a numbers game, though. One link from a “trusted authority” site in Google could be all you need to rank high in your niche. Of course, the more “trusted” links you attract, the more Google will trust your site. It is evident you need MULTIPLE trusted links from MULTIPLE trusted websites to get the most from Google in 2020.
Other research shows that exact-match domains that are deemed to be relevant, valuable, and high-quality can see a ranking boost because of it. However, if you already have an established website, you don’t need to go looking for an exact-match domain for your business; focus on a URL that reflects your business and optimize the heck out of it instead!
The errors in technical SEO are often not obvious, and therefore one of the most popular. Mistakes in robots.txt and 404 pages, pagination and canonical URLs, hreflang tags and 301 redirects, http vs https and www vs non www versions: each of them can seriously spoil all efforts to promote the site. One quality SEO website analysis is enough to solve all the main problems in this part forever.

I think it makes sense to have unique content as much as possible on these pages but it’s not not going to like sync the whole website if you don’t do that we don’t penalize a website for having this kind of deep duplicate content and kind of going back to the first thing though with regards to doorway pages that is something I definitely look into to make sure that you’re not running into that so in particular if this is like all going to the same clinic and you’re creating all of these different landing pages that are essentially just funneling everyone to the same clinic then that could be seen as a doorway page or a set of doorway pages on our side and it could happen that the web spam team looks at that and says this is this is not okay you’re just trying to rank for all of these different variations of the keywords and the pages themselves are essentially all the same and they might go there and say we need to take a manual action and remove all these pages from search so that’s kind of one thing to watch out for in the sense that if they are all going to the same clinic then probably it makes sense to create some kind of a summary page instead whereas if these are going to two different businesses then of course that’s kind of a different situation it’s not it’s not a doorway page situation.” John Mueller, Google 2017

That content CAN be on links to your own content on other pages, but if you are really helping a user understand a topic – you should be LINKING OUT to other helpful resources e.g. other websites.A website that does not link out to ANY other website could be interpreted accurately to be at least, self-serving. I can’t think of a website that is the true end-point of the web.
You pay each time a user clicks on an SEM result. You pay nothing when a user clicks on an SEO result. SEM results are paid placements, and your brand is charged each time a user clicks on the result. Therefore, you must have a budget for continually showing SEM ads and using this form of PPC lead generation. On the flip side, you are never charged when a user clicks on an organic search result.
Don’t underestimate these less popular keywords. Long tail keywords with lower search volume often convert better, because searchers are more specific and intentional in their searches. For example, a person searching for "shoes" is probably just browsing. On the other hand, someone searching for "best price red womens size 7 running shoe" practically has their wallet out!

Additionally, there are many situations where PPC (a component of SEM) makes more sense than SEO. For example, if you are first launching a site and you want immediate visibility, it is a good idea to create a PPC campaign because it takes less time than SEO, but it would be unwise to strictly work with PPC and not even touch search engine optimization.
Additionally, there are many situations where PPC (a component of SEM) makes more sense than SEO. For example, if you are first launching a site and you want immediate visibility, it is a good idea to create a PPC campaign because it takes less time than SEO, but it would be unwise to strictly work with PPC and not even touch search engine optimization.
QUOTE: “For instance, we would see a lot of low-quality posts in a forum. We would index those low-quality pages. And we’d also see a lot of really high-quality posts, with good discussions, good information on those pages. And our algorithms would be kind of stuck in a situation with, well, there’s a lot of low-quality content here, but there’s also a lot of high-quality content here. So how should we evaluate the site overall? And usually, what happens is, our algorithms kind of find some middle ground……. what you’d need to do to, kind of, move a step forward, is really try to find a way to analyze the quality of your content, and to make sure that the high-quality content is indexed and that the lower-quality content doesn’t get indexed by default.” John Mueller, Google 2014
Website:  Websites are a great way to establish your brand identity. They can use text, images, audio, and video elements to convey the company's message, as well as inform existing and potential customers of the features and benefits of the company's products or services. The website may or may not include the ability to capture leads from potential customers or directly sell a product or service online. 
Does this article have an excessive amount of ads that distract from or interfere with the main content? (OPTIMISE FOR SATISFACTION FIRST – CONVERSION SECOND – do not let the conversion get in the way of satisfying the INTENT of the page. For example – if you rank with INFORMATIONAL CONTENT with a purpose to SERVE those visitors – the visitor should land on your destination page and not be deviated from the PURPOSE of the page – and that was informational, in this example – to educate. SO – educate first – beg for social shares on those articles – and leave the conversion on Merit and slightly more subtle influences rather than massive banners or whatever that annoy users). We KNOW ads (OR DISTRACTING CALL TO ACTIONS) convert well at the top of articles – but Google says it is sometimes a bad user experience. You run the risk of Google screwing with your rankings as you optimise for conversion so be careful and keep everything simple and obvious.
QUOTE: “The quality of the MC is an important consideration for PQ rating. We will consider content to be Low quality if it is created without adequate time, effort, expertise, or talent/skill. Pages with low quality MC do not achieve their purpose well…. Important: The Low rating should be used if the page has Low quality MC. ” Google Search Quality Evaluator Guidelines, 2019
QUOTE: “… it also includes things like the comments, includes the things like the unique and original content that you’re putting out on your site that is being added through user-generated content, all of that as well. So while I don’t really know exactly what our algorithms are looking at specifically with regards to your website, it’s something where sometimes you go through the articles and say well there is some useful information in this article that you’re sharing here, but there’s just lots of other stuff happening on the bottom of these blog posts. When our algorithms look at these pages, in an aggregated way across the whole page, then that’s something where they might say well, this is a lot of content that is unique to this page, but it’s not really high quality content that we want to promote in a very visible way. That’s something where I could imagine that maybe there’s something you could do, otherwise it’s really tricky I guess to look at specific changes you can do when it comes to our quality algorithms.” John Mueller, Google 2016

SEO is an acronym for "search engine optimization" or "search engine optimizer." Deciding to hire an SEO is a big decision that can potentially improve your site and save time, but you can also risk damage to your site and reputation. Make sure to research the potential advantages as well as the damage that an irresponsible SEO can do to your site. Many SEOs and other agencies and consultants provide useful services for website owners, including: