The answer is Yes. SSL will protect information like your customers' details, credit card information, etc that is being submitted on your site.Do you have a website where customers have to log in or fill a web form? If yes, it is important that you have SSL installed on such site to secure the collected data, protect your site from data bridge and avoid losing the credibility of your website.
SSL certificates can also be used on web servers for Internet security and mail servers such as IMAP, POP3, and SMTP for mail collection / sending security.