Any website needa a SSL certificate does not matter if there are managed or not pesonal details.
If someone access in browser a website that has not SSL installed he will get a message that that website may be dangerous. Your visitors will go away before seeing it.

Search engines are cracking down on perceived ‘non-secure’ websites. Any websites without the SSL certificate will remain http while those with encryption will show https in users’ browsers. Chrome, Firefox and other browsers have began issuing warnings that non-https sites are insecure.
Additionally, Google recently announced SSL is a ranking signal, so unless you have SSL your site will be harder to find, impacting on your traffic and revenue.