A quote from their blog: From Yahoo!'s point of view, any type of signed-in individual engaging with Yahoo! services is a valued customer, whether she verifies utilizing a Yahoo!, Facebook, or Google ID.
Yahoo Sign In Facebook
Login to Yahoo Mail account on PC/Desktop computer
First you require a username and also password; currently open web browser from your computer/desktop. Then open web page www.yahoomail.com on it. To start their new "one-click" sign-in just click the "Sign in with: Facebook" symbol on the Yahoo! login display. That's all you need; to get 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 must be your internet browser. Safari is the best surfing option for Mac OS; Safari fasts, quicker 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 and type www.yahoomail.com; you will be guided to Yahoo mail sign-in page. To start their new "one-click" sign-in merely click the "Sign in with: Facebook". You are then fully signed into Yahoo!
Nevertheless, a recommendation- you still will not be able to authorize into a mobile or desktop customer making use of Google OpenID.
I hope this short article can help you. Thank you ...