DreamHost, the hosting that I use for this blog, among other things, has automated the generation and installation of Let's Encrypt SSL certificates. This wiki page contains all the necessary information to set up your system.
Why should you do this? Others have answered this question quite well: It's time to encrypt the entire Internet.
At the time of this writing, all blogs under the rinzewind.org domain (this one, plus my Spanish one) work with SSL. In a few days this will be the default option.