Today my server told me that was added "Let's Encrypt"
Let's Encrypt - Free SSL/TLS Certificates. A free open source ssl certificate.
I Googled a bit, an ssl certificate seems good and right thing. Matt says, the google algorithm considers him and maybe puts a bit higher up the sites that use it. Google is also a sponsor of Let's Encrypt.
But Googling a little longer, I saw that, the biggest adult sites do not seem to use ssl ...
So, considering it was free, SSL yes, or SSL not ???
Last thing, my sites are online for some years, I would say "good" indexed. Adding ssl, and changing all the http to https, risk of creating some trouble?