This is where Google Sitemaps can be useful. Basically, having Google Sitemaps helps search engines identify what are the pages found within the site especially when it is impaired by poor navigation structure or non-search friendly menu system. Without necessarily crawling its way through the site, Googlebot for example makes use of this file to identify which pages it needs to visit.
The question now is that if we covered all bases, meaning that if our websites have good navigation structure, uses text links or employs breadcrumb menu system, is the use of Google Sitemap a necessary step?
Taken from Search Engine Roundtable, here are the possible benefits of not bypassing the use of Sitemap file.
- Help with canonical URLs. For example, by submitting your / and not your /index.html page, Google might just figure that / is the main URL and it will help with those canonical issues for that case. Of course, a 301 redirect from /index.html to / would do the same and Google recommends that even with a sitemap file, you 301 redirect URLs like those.
- The Last modification date field in the sitemap file can aid Google in quickly locating the actual change in the page. John at Google explained that Google might not have time to crawl all the pages you said changed, so if you specify the actual change in the Sitemap file, it will be easier for Google to pick up on those changes.
- The Priority, Change frequency is a lot like the last mod date, said John. If you give Google data that “makes sense”, i.e. don’t list 100% of your pages as the most important page on your site, then it can be useful to Google.
Looking back to the file I was talking about earlier, it appears that a Sitemap file is necessary. However, for sites that have good on-page SEO and promote healthy internal linking structure, having a Sitemap file is more of an assurance that ensures that search engines, particulrly Google, to find pages they are looking for.