Lately I've been contacting the clients that host websites at I Design about the importance of adding Transport Layer Security or a Secure Sockets Layer certificate (SSL) to their website hosting package. In the past, SSL was reserved for websites that shared sensitive data with users or sold products. But that has changed and in today's world, secure websites are a must.
We now automatically install SSL certificates on all new accounts. And when we add SSL certificates to existing sites, we modify the site settings to automatically route traffic to the new https domain. This helps bookmarks or links that are already on other sites get properly rerouted to the new https pages.
With their HTTPS everywhere initiative, Google is really pushing sites to install SSL certificates. So not only does it help secure your site, it helps with your overall SEO. That alone should be reason enough. Also, web browsers will eventually start showing warnings for non-secure sites, so it's better to be proactive.
If you'd like to read more, here's a link to an article on Forbes.com that goes into more detail.