The biggest advantage any one provider has over another is experience and resource. The knowledge of what doesn’t work and what will hurt your site is often more valuable than knowing what will give you a short-lived boost. Getting to the top of Google is a relatively simple process. One that is constantly in change. Professional SEO is more a collection of skills, methods and techniques. It is more a way of doing things, than a one-size-fits-all magic trick.
When referring to the homepage, a trailing slash after the hostname is optional since it leads to the same content ("" is the same as ""). For the path and filename, a trailing slash would be seen as a different URL (signaling either a file or a directory), for example, "" is not the same as "".
Provide full functionality on all devices. Mobile users expect the same functionality - such as commenting and check-out - and content on mobile as well as on all other devices that your website supports. In addition to textual content, make sure that all important images and videos are embedded and accessible on mobile devices. For search engines, provide all structured data and other metadata - such as titles, descriptions, link-elements, and other meta-tags - on all versions of the pages.

The basics of GOOD SEO hasn’t changed for years – though effectiveness of particular elements has certainly narrowed or changed in type of usefulness – you should still be focusing on building a simple site using VERY simple SEO best practices – don’t sweat the small stuff, while all-the-time paying attention to the important stuff  – add plenty of unique PAGE TITLES and plenty of new ORIGINAL CONTENT. Understand how Google SEES your website. CRAWL it, like Google does, with (for example) Screaming Frog SEO spider, and fix malformed links or things that result in server errors (500), broken links (400+) and unnecessary redirects (300+). Each page you want in Google should serve a 200 OK header message.
Length of site domain registration; (I don’t see much benefit ON IT”S OWN even knowing “Valuable (legitimate) domains are often paid for several years in advance, while doorway (illegitimate) domains rarely are used for more than a year.”) – paying for a domain in advance just tells others you don’t want anyone else using this domain name, it is not much of an indication that you’re going to do something Google cares about).
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.
I used to think it could take more to get a subfolder trusted than say an individual file and I guess this sways me to use files on most websites I created (back in the day). Once subfolders are trusted, it’s 6 or half a dozen, what the actual difference is in terms of ranking in Google – usually, rankings in Google are more determined by how RELEVANT or REPUTABLE a page is to a query.
When Google trusts you it’s because you’ve earned its trust to help it satisfy its users in the quickest and most profitable way possible. You’ve helped Google achieve its goals. It trusts you and it will reward you with higher rankings. Google will list “friends” it trusts the most (who it knows to be reputable in a particular topic) at the top of SERPs.

SEO is the practice of optimizing websites to make them reach a high position in Google’s – or another search engine’s – search results. At Yoast, we believe that holistic SEO is the best way to rank your website because you focus on making every aspect of your site awesome. Don’t use any black-hat SEO tricks, because eventually, this will have negative consequences for your rankings. Instead, practice sustainable SEO, with your user in mind, and you will benefit in the long run.