You need an SSL certificate if you are handling any sensitive customer data. Ecommerce sites, which usually handle credit card payments, definitely need an SSL certificate. A site that allows for personal or private communication — email, messaging, file storage — needs a certificate.
Even if you don’t have a specific requirement for an SSL security certificate, you may want to get one anyway. A number of organizations have recognized that HTTPS promotes safer browsing generally. Google agrees with this, and actually provides an SEO benefit to sites that use HTTPS as an incentive to encourage more sites to adopt it.
