SSL has become increasingly important in the past couple of years, not only for securely transmitting information to and from your website, but also to increase visibility and lower the chances of being penalized.
SSL allows a website to be accessed over HTTPS, which encrypts data sent between visitors and web servers. Since 2014, SSL has been a ranking signal for SEO. Now, Google has started to flag non-HTTPS websites that transmit password and credit card data.