Google Webmaster Trends Analyst, Garry Illyes, posted on Google+ early this morning with a clear message to site owners: “please tell search engines about your HTTPS URLs!”
According to a small scale analysis of indexed URLs, over 80% of HTTPS URLs that are eligible for indexing are instead being displayed as regular HTTP URLs because Google isn’t aware of the HTTPs variant.
HTTPS URLs cannot become canonical (HTTP redirecting to HTTPS) until Google is notified about them. Instead, what most site owners are doing is using the HTTP URLs in sitemap files, in the rel-canonical and rel-alternate-hreflang elements.
Using the HTTPS version of your URLs in those instances would be perfectly fine, Illyes says. If your site supports HTTPS, use those HTTPS URLs everywhere so Google knows about them
Many site owners have been migrating to HTTPS since Google announced back in August that it would grant a slight ranking boost. The problem is that the majority of them are moving to HTTPS and then leaving it at that.
Moving to HTTPS is not a ‘set it and forget it’ type of change. As you migrate your site to HTTPS it’s important to make sure Google is aware of your new URLs.
It’s almost like an old fashioned change of address, if you don’t notify the postal company they won’t know where to send the mail. Well if you don’t let Google know where to find your HTTPS URLs it won’t know where to find them. That means they won’t be indexed, let alone receive any kind of ranking boost.