In a Business to Consumer scenario, what role does Facebook fulfill?

In a Business to Consumer scenario, Facebook functions as an Identity Provider. This means that Facebook provides authentication services that allow users to log into various applications and websites using their Facebook credentials. When users choose to "Sign in with Facebook," they are leveraging Facebook's identity management capabilities, which simplify the login process while maintaining security for the user.

As an Identity Provider, Facebook handles the verification of user identities, facilitating authentication without requiring users to create and remember additional usernames and passwords specific to each service they wish to access. This streamlines user interaction with multiple platforms and enhances overall convenience.

The other options, while relevant in different contexts, do not accurately describe Facebook's primary role in a Business to Consumer scenario. For instance, a Service Provider usually offers services directly to consumers, which can encompass various applications and platforms beyond identity. An Application Developer refers to the entities creating apps that utilize Facebook’s services, and a Data Controller pertains to organizations that determine the purposes and means of processing personal data, which is distinct from the identity management functions that Facebook primarily provides.