Google has, since 2014, been giving sites with a secure certificate installed a boost within their ranking algorithm. Google has been telling web masters for years that it is safe and indeed now beneficial for users to switch from HTTP to HTTPS.
Based on their own internal tests Google has said that the change impacted fewer than 1% of global search queries most importantly they said they may decide to strengthen the weight applied to a secure site because they want to encourage all website owners to switch from HTTP to HTTPS to keep everyone safe on the web.
It should not really come as any surprise that Google prefers sites that are trusted and certified using an SSL certificate. This is because users clicking onto secure websites can be guaranteed that the their information will be handled securely.
Google and other search engines have decided that an SSL is an important indicator as to the quality of a website so whether you’re handling multi million pound transactions or posting the odd blog post an SSL certificate isn’t just about security any more.