Swoop is similar to using your Facebook or Twitter account to sign in. Both are letting you use one account to sign into many other accounts. With Facebook or Twitter, you use that account to login to other sites. With Swoop, you use your personal email account.
Email addresses 100% of your customers, social media accounts do not. First, it’s important to realize that every online account already requires an email address as part of the account profile. So everyone account can use their email address to log in. Second, only a portion of your customers might have a social media account and a much smaller portion are willing to use it for login. What this all means is that the email account makes it possible completely drop the password from your site. Something that you cannot do by just offering social signin. The ideal solution is to offer both and give your customers a choice, but be careful not to offer too many or you will make your login page look like a Nascar with 20 different logos on it!