A quote from their blog: From Yahoo!'s perspective, any signed-in user involving with Yahoo! solutions is a valued customer, whether she authenticates using a Yahoo!, Facebook, or Google ID.
Yahoo Mail Sign In With Facebook
Login to Yahoo Mail account on PC/Desktop computer system
First you require a username as well as password; currently open web browser from your computer/desktop. Then open page www.yahoomail.com on it. To launch their new "one-click" sign-in just click the "Sign in with: Facebook" symbol on the Yahoo! login display. That's all you require; to obtain access 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 have to be your web internet browser. Safari is the most effective browsing service for Mac OS; Safari is quick, quicker as well as 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. Merely open Safari and type www.yahoomail.com; you will be guided to Yahoo mail sign-in web page. To start their brand-new "one-click" sign-in simply click on the "Sign in with: Facebook". You are then fully signed into Yahoo!
Nonetheless, an advice- you still will not have the ability to authorize into a mobile or desktop computer client using Google OpenID.
I hope this article could help you. Thank you ...