QUOTE: “The preferred domain is the one that you would liked used to index your site’s pages (sometimes this is referred to as the canonical domain). Links may point to your site using both the www and non-www versions of the URL (for instance, http://www.example.com and http://example.com). The preferred domain is the version that you want used for your site in the search results.” Google, 2018
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.
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.
However, we do expect websites of large companies and organizations to put a great deal of effort into creating a good user experience on their website, including having helpful SC. For large websites, SC may be one of the primary ways that users explore the website and find MC, and a lack of helpful SC on large websites with a lot of content may be a reason for a Low rating.
An SEO audit should not be rushed. It simply takes time to uncover root causes of the issues affecting your online health. Depending on the size of your site, a proper audit can take anywhere from 2-6 weeks to complete. Due diligence is required when making major changes to any website, and an SEO specialist must conduct a thorough investigation to make accurate, impactful recommendations.