A quote from their blog: From Yahoo!'s perspective, any kind of signed-in individual engaging with Yahoo! services is a valued individual, whether she confirms making use of a Yahoo!, Facebook, or Google ID.
Sign In Yahoo Using Facebook Account
Login to Yahoo Mail account on PC/Desktop computer system
First you need a username and password; currently open web internet browser from your computer/desktop. Then open web page www.yahoomail.com on it. To initiate their new "one-click" sign-in merely click the "Sign in with: Facebook" symbol on the Yahoo! login display. That's all you require; to obtain accessibility of your Yahoo mail account.
Login to Yahoo Mail account on Mac computer system
If you are a user of Mac computer system then Safari must be your internet browser. Safari is the most effective surfing solution for Mac OS; Safari is quick, much faster and easy to use web browser. You can conveniently access your Yahoo Mail account with it. See, how you can login with Yahoo mail account on Safari web browser. Simply open Safari as well as type www.yahoomail.com; you will certainly be directed to Yahoo mail sign-in web page. To initiate their new "one-click" sign-in simply click the "Sign in with: Facebook". You are then fully signed right into Yahoo!
Nevertheless, a word to the wise- you still will not be able to authorize into a mobile or desktop computer client making use of Google OpenID.
I hope this short article can assist you. Thank you ...