Social logins allow visitors to use existing login information from social networking sites like Facebook, Twitter or Google Plus to sign into third-party sites (1).
It's most broadly used to authenticate the user, or verify the user's identity, but it can also be used as an authorisation mechanism to allow users to post site content to their social networks. When used in this way, social logins are often implemented using OAuth, a secure protocol that grants third-party applications a "session token" so they can post to providers on behalf of the user.
For the consumer, the main advantages of social logins are speed and convenience. Signing in with a social login generally takes just seconds. And when they use a social login, they're spared from creating a new login account and remembering a new password for the site. Integrated social posting also makes sharing content from third-party sites across their social networks more convenient.
For online retailers and Web developers, social logins can provide multiple benefits, including richer user data, more registration and greater social promotion.
When retailers offer social login, they can gather valuable insights about a user's demographics and social network. This info can include the user's public profile, address, hometown, phone number, email address, likes, and Facebook friend list or Twitter following list. With Facebook, Web and app developers are able to tailor which information they request from the consumer, which may help overcome privacy hesitations from the user. Retailers may be required to demonstrate how the information they access will be valuable to the consumer, such as when using a consumer's likes to curate product offerings (2).
Social login has also been shown to boost registration for third-party sites. More than 90 percent of consumers say they've left a site rather than complete a traditional registration system, according to market research firm Janrain (3). The firm's data shows that offering social login can increase registration conversion by more than 50 percent.
For consumer sites that offer social functionality, such as commenting, sharing or gaming features like earning badges, social login allows for easier engagement. That social activity can be a cost effective, user-generated means of marketing your site and its products.
Many sites that offer social login also offer traditional online registration so that customers who don't have a social networking account or don't wish to employ social login aren't precluded from registering on the site. That can be particularly appealing for consumers who have expressed privacy concerns over social login.
1. "Sign in with Twitter"