Google is giving more weight to HTTPS but at the same time Google also wants to penalize for slower websites. And it seems that HTTPS takes longer to load than non-HTTPS.
“Moreover it takes more time to get a HTTPS webpage rendered on Browser when compared to a HTTP webpage. This is due to the required negotiation time of the server to authenticate the GET request.”
They even write that:
“There is absolutely no need to serve a HTTPS webpage, when there is no question of any privacy.”
So for non-memberships sites you wouldn’t need to serve HTTPS pages. It makes it really questionable what is the best thing to do. Joost de Valk did the transition awhile back. The document on WordPress has been written a while ago, however the push from Google is quite recent. There is a global need for better online security in particular with websites running on WordPress or Joomla.
Why use SSL?
Trust factor is a big part of using SSL on your website, when a visitor sees that you have taken the effort to get your organization verified or at least have a trusted “green padlock” in your url then things seem more legit. The painful thing is when you keep receiving the mixed content messages. So you have to be very thorough in making sure everything is being delivered securely.
There are many other factors at play in ranking. Page load time does impact the way you rank, but its not a main factor and certainly not the only one. Other things such as a good Schema.org markup can improve your ranking as well. Yoast has the following experience with SSL and SPDY:
So. HTTPS doesn’t have to be slower, there’s obviously a tiny bit of overhead but then things like SPDY are actually faster than “old” HTTP implementations.
If you need HTTPS on a part of your domain, doing it for the entire domain means you can cache resources much more easily, use a CDN better, etc. So… Just make the move.
Google’s SSL SPDY could be a solution
Well, you can only use Google’s SPDY if you have your own server. If you don’t you could use CloudFlare. They have been offering SPDY to customers with SSL since 2012. If you switch over full SSL be sure your cdn supports SPDY or else you will reduce the speed of your website. SSL will make your site slower unless EVERYTHING is loaded over SPDY. And it depends on how your SSL has been configured.
Should you make the switch?
Probably, just make sure your Google Ads keep working, your files are loading securely, you change your HTTP links into HTTPS etc etc.