An excerpt from from TechCrunch notes that: Yahoo and its roughly 250 million user IDs officially jump on the bandwagon today 1/17/2008. Previously, there were only approximately 120 million valid OpenID accounts. In one move, Yahoo more than triples that number. The service will be available in public beta on January 30, says Yahoo (see openid.yahoo.com), and will allow users to log in to more than 9,000 OpenId compliant websites with their Yahoo IDs. Yahoo will also be integrating their Sign-In Seal feature, meaning users can view an uploaded image before giving over credentials - the feature is widely used by financial institutions and is designed to reduce the effectiveness of phishing attempts. Yahoo is also announcing that both Plaxo and JanRain will allow Yahoo OpenID sign-ins from January 30.
A Retrospective on the OpenID contemplation by the Big 3
The big idea in OpenID is providing a decentralized single sign-on platform. Single sign-on is not a new notion however. Almost all the internet giants, like Yahoo, Google and MSN, use single sign-on across their properties to lower the threshold of accessing their services and to create a competitive advantage. The reason they do this is that signing up is actually a big barrier to entry for users of web apps. Users feel more comfortable when they don't have to sign up to use an app - it's much easier to give it a try and it's less time-consuming to start using it. That's why most web sites today try to keep sign up process as short as possible. Here's a graph which illustrates this:
From this point of view, OpenID can be seen to resemble Yahoo - the biggest single sign-on strategy player in the history of the Internet.
Obviously Yahoo saw this resemblance as well and rose to the occasion of adopting this standard that takes a giant step forward in creating a more seamless landscape across the Internet - Bada bing, bada-boom!