SEO consists of a large number of factors, which traditionally bring us back to the three previously mentioned pillars: content, indexing and authority. The pillars themselves have not changed over the years, however the content and weighting (relevance) of the pillars do.
It is often said that Content is King. A statement used by many online marketers and agencies. This refers not only to content (text/information) but to relevant and unique content. Relevant and unique content is important in the entire website: search engines like Google do no longer look at individual pages within a website, but they gain a general impression based on all the pages of a website. Some “bad pages” (pages without content or without unique/relevant content) can have a negative effect on the entire website (therefore also on pages with unique and relevant content). The content must match the target audience visiting the website. What you need is a content strategy written for the target audience, where your focus is on a few important keywords that match the target audience. A preliminary extensive keyword research is essential prior to determining the most relevant SEO structure.
Content is not only about writing unique and relevant texts. Other important elements within content are: implementing rich snippets, creating unique meta tags, using heading tags, having a clear URL structure that matches the content, adding alt texts to images and using text elements (bold text, links to relevant pages that make navigating easier for visitors), etc.
Indexation is a part of SEO which involves the way in which search engines can reach, scan and evaluate a website. It involves questions like: what information/pages may/may not be indexed by a search engine? What can/can not be scanned and evaluated by a search engine? How to deal with situations that might be classified as SPAM? Many factors affect indexation. Site speed (website speed) for example has become an important factor: how easily can a search engine reach a page and how fast can all the information on a page be scanned and evaluated? Furthermore Google announced in 2014 that websites using a secure HTTPS connection, have a slight advantage in terms of ranking (see the official article of Google on Google Webmaster Central Blog ). Google focuses on making the internet safer, faster and more relevant. The transition from HTTP/2 is also important (see also the article about HTTPS en HTTP/2 written by AdResults (in Dutch) for Twinkle Magazine). In addition, there are many new relevant factors, which a few years ago had no influence on the ranking. For example having a mobile friendly website is now of great importance (read more about this in the article written (in Dutch) by AdResults about mobile-friendly websites ).
Indexation also includes solving problems within websites, such as duplicate URLs. There are a number of solutions to deal with indexation problems, for example using robots.txt, meta robots, applying redirects and/or canonical URLs. Many websites are facing problems because the web page is available with and also without a trailing slash, the URLs can be written in both lowercase and uppercase letters etc. In these cases there are two (or more) URLs available for one page. Which page is then indexed by a search engine such as Google? If you use website filters within your website, did you carefully consider how this should be built in an SEO friendly way, to prevent Google from crawling thousands of filter URLs?
Authority is an important factor: links to pages (both external and internal links) are seen by search engines as recommendations. More links to a page mean higher popularity. It is important that these are links from qualitative websites, preferably with a high popularity that match the content of the website (relevant links). Usually we talk about external links, which are links from other external websites. Internal links are also very important. If many pages within a site refer to a specific internal page, then that page has high internal link popularity. A good internal linking structure is therefore essential: it places the emphasis on the important pages and does not put the focus on the less important pages. Also within link popularity there are Google guidelines: paid links should not contribute to the link popularity, links using a nofollow tag do not count in the link popularity, link farms are not allowed, anchor texts (the visible, clickable text in a hyperlink to which a link is attached to) are very important and Google may penalize unnatural link patterns. Previously, obtaining authority consisted mainly out of linkbuilding. Nowadays gaining authority through social media has become more and more important (getting Facebook likes and shares, + 1’s from Google, Tweets, etc.).
SEO tools or software solutions are essential in optimizing SEO. By using these tools we can detect website problems that without them would probably be overlooked. Besides the many commercial tools available on the market, Google itself offers a very useful (free) tool: the Google Search Console (formerly the Google Webmaster Tools). The Google Search Console provides insight into the problems that Google encounters when crawling your site and offers possibilities to resolve the issues on your site.