Notes from the Google Webmaster Hangout on the 9th of March 2018.
Googlebot Crawls Known URLs Faster Following Significant Site Changes
Googlebot will crawl known URLs faster if it detects that significant changes have been made across the site to things like structured data, rel canonicals or redirects.
Consider evaluating category pages to see if they can be merged to make even stronger ones, especially if two category pages are ranking for similar clusters of queries.
Collecting Reviews Independently or Through Third Party is Fine From SEO Perspective
It doesn’t matter if you collect reviews by yourself or through a third party, it makes no difference from an SEO perspective.
Only Use Submit to Index When Critical to do so
Only use Submit to Index feature in Search Console when it is critical to do so e.g. for a new site that Google hasn’t seen before. Manual submission is not necessary for the addition of new pages as Google can find these through the normal means of crawling a site.
Googlebot Will Likely See US Version of Localised Text Using JS
Web Spam Team Takes Action Based on Patterns Found in Spam Reports
Google’s Web Spam Team goes through spam reports regularly and take action looking at larger patterns rather than taking manual action based on individual reports.
Google Aims to Neutralise Spam by Being as Specific as Possible in Action Taken
Google take action against spam in different ways. Sometimes they will neutralise a spammy technique and other times they may remove a site completely from the index. In general Google try to be as specific as possible when dealing with spam as it isn’t always a case of intentionally trying to abuse Google’s algorithms.
Google Can Understand International Sites Without Hreflang Guidance
Hreflang is best practice for international sites. However, Google can understand different language versions of a site without hreflang present through internal linking or the URLs themselves.
Video Removal From Index Can Take Time
If you remove a video from your site it can take some time to be removed from the index even if markup and sitemap links are removed because Google needs to be sure it has actually been removed.
There is no Inherent SEO Advantage to Having Clean Semantic HTML
Google doesn’t look at HTML5 semantically. Having clean semantic HTML is beneficial for implementing structured markup properly and having a page that works well across different devices but it carries no inherent SEO advantage.