Google recently introduced the WebFinger protocol and enabled it for all Gmail account.
What is WebFinger?
WebFinger is a protocol that can be used to attach public profile information to an email address. Engineers have been fumbling around with ways to standardize the way profile information is shared for years. Remember OpenID? Or Facebook Connect? Many of these products have major shortcomings. With OpenID, users have to remember a provider URL and yet another account login. With Facebook Connect, we're at the mercy of Facebook with regards to how data is handled.
The interesting thing about WebFinger, is that information can be attached to an email address. Email is required for just about anything you do on the web so it makes sense that data about a profile should be attached to it.
WebFinger is about making already public information more easily discoverable, not uncovering private data.While a WebFinger profile may have information about the location of a user's Facebook profile, it won't contain data secured by Facebook.
What kind of profile data can you get from WebFinger?
WebFinger can support all kinds of data. Really, just about anything digital can in some way or another be added to a WebFinger profile. WebFinger data is delivered as XML and can include references to the source of the data, not just a copy of it. For example, if you have a public profile somewhere, and WebFinger knows about it, WebFinger would just display the URL to that public profile, not a copy of the data in it.
Google's implementation of WebFinger publishes user hCards, OpenID provider, Google public profile info, and other neat stuff.
What can marketers do with this?
What might be of obvious use is the amount of data that could be pulled down about a user. The data is public already, so there should be no problems with discovering and analyzing the data.
I think the more interesting application will be with the convenience the data can provide for users. For example, imagine a form where you want to gather a user's contact information. The form could be built so that as soon as the user enters an email address, WebFinger is used to prepopulate the form with the user's contact information.
What can be done today?
Obviously, this is still an emerging technology. However, the protocol is open and ready for experimentation. One idea is to create forms that enable WebFinger capabilities for Gmail users. Or, your organization could host your own WebFinger server to link public data about your employees. We'd love to hear from anybody building practical applications for WebFinger.