Single Sign-In

Interesting reading today. AOL is now promoting its Screen Name Service as a single sign-in across multiple services and web sites. Sound familiar?

Single sign-in. Hard to believe as an end user that this is the next killer app that Microsoft and AOL are going to fight over. After all, isn’t instant messaging more important? Certainly to the end user it is…

But that may be the issue. It’s hard to make a case that single sign-in is a compelling technology for the end user. But it’s also hard to make the case that instant messaging has much of a business case around it, except as a feature that compels vendor platform loyalty. IM buys lock-in as long as IM platforms are proprietary and don’t interoperate. But it doesn’t do anything else for the platform vendor except drive a lot of headaches. Look at the collapse of the MSN messenging service a few weeks ago–an expensive public relations nightmare from something that doesn’t drive revenue. And I hesitate to think how much AOL spends on revving their protocol and platform so all the AOL clones out there break every month or two.

So what’s compelling about single sign-in for Microsoft and AOL? Microsoft’s Passport, as part of its Hailstorm services, is a big cornerstone of the .NET platform of value added services they’re rolling out on top of SOAP. It’s the authentication part of .NET — and the information store. You keep your information (as much of it as you want) in the service, and you have discretion about how other sites access it. AOL’s service is much the same.

There are some important differences between the services, or at least the way that they’re being rolled out. AOL’s sign-in services are limited to web sites; the Hailstorm service is supposed to be accessible across multiple devices, including Stinger, PocketPC, and the Xbox (I suppose for online gaming, although it might be useful for online registration too).

I think Microsoft is thinking bigger than AOL on this one. It’s already a few steps ahead. While it’s not clear how a web site can use AOL’s Screen Name Service to drive revenues, besides gaining customer loyalty, Microsoft’s got a whole new platform waiting in the wings that businesses can take advantage of to offer value added services to customers once they’ve signed in with Passport. Think all the wireless carriers, for instance, will turn down an opportunity to make additional revenue per subscriber? You haven’t been looking at their financial statements.

Dave Winer thinks that single sign-in is important too. His model places membership data in the cloud–allowing multiple players to host the information. I’ve heard that language from Microsoft too. Dave wants to take the work that AOL and others have done and unify it behind a common XML-RPC/SOAP interface. Here’s the $64 (million) question: is it enough to interoperate? Can distributed membership and preferences get enough momentum to become the de facto standard?

Eventually standard wars end. We are, for all intents and purposes, in a one-browser, one-client-OS world (although I use other browsers and other OSes, I’m not statistically significant). That happened because of the compelling benefits of being on one platform. I think single sign-in is going to be a major battle in the war for the next Internet platform.