According to newly-released data from Janrain, Google is gaining popularity for use as an authentication/login system within third-party web applications and websites. During Q4 2013, Facebook remained flat with 45% share of logins, compared to Google's gain of 2.5% points. Google's marketshare for social logins is about 35%. This 10% difference between the two is growing more narrow--and has never been closer than now.
Twitter trails Google, Facebook and Yahoo with 5.7% social login marketshare.
Google recently updated it's Google+ sign-in system to make it easier for web development and the creation of third-party applications and websites. The updates included:
SOURCE: Janrain, Social Login Trends Across the Web for Q4 2013, https://janrain.com/blog/social-login-trends-across-the-web-for-q4-2013/