An alternative to Facebook has been gaining momentum in recent weeks and has its sights on reaching 400 million users by the end of 2012, Bloomberg reports.

Google’s answer to Facebook, Google+, saw almost one-quarter of its total consumer base join in December, the story reports, citing Ancestry.com founder Paul B. Allen, who tracks the service’s stats. The sudden boom means that Google is adding 625,000 new users per day and could end 2012 with 400 million users, the story notes.

The growth spurt comes after the social-networking service got off to a slow start, as previously reported.

Facebook has more than 800 million members.