A quote from their blog: From Yahoo!'s viewpoint, any kind of signed-in individual engaging with Yahoo! services is a valued customer, whether she validates using a Yahoo!, Facebook, or Google ID.
Yahoo Mail Sign In With Facebook
Login to Yahoo Mail account on PC/Desktop computer
First you need a username and also password; now open internet browser from your computer/desktop. After that open web page www.yahoomail.com on it. To start their brand-new "one-click" sign-in just click on the "Sign in with: Facebook" icon on the Yahoo! login screen. 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 customer of Mac computer after that Safari should be your web browser. Safari is the very best browsing remedy for Mac OS; Safari is quick, quicker and also easy to use web browser. You can conveniently access your Yahoo Mail account with it. See, how to login with Yahoo mail account on Safari web browser. Just open Safari as well as kind www.yahoomail.com; you will certainly be routed to Yahoo mail sign-in web page. To launch their brand-new "one-click" sign-in simply click the "Sign in with: Facebook". You are then totally authorized right into Yahoo!
However, an advice- you still won't have the ability to sign into a mobile or desktop computer customer using Google OpenID.
I wish this article could aid you. Thank you ...