Richard Nieva/CNET

Google on Thursday announced it has acquired the startup Polar, which specializes in online polls, signaling that the search giant is still investing in its fledgling social network. Terms of the deal were not disclosed.

The team will work on Google+, the search giant's social network, which hasn't had the same kind of traction as Facebook, the world's biggest social community with more than a billion users. By contrast, Google said in October that Google+ has 300 million "in-stream" users -- or people who actively view the main news page or feed.

Polar, founded last year, polls users on smartphones and tablets by letting them choose between two things -- for example: Coke versus Pepsi, or Warriors versus Lakers. The startup has served more than half a billion polls in the past eight months and had 1.1 million active voters in September, according to a blog post by founder Luke Wroblewski.

Google will shutter support of the service by the end of the year. In a statement, Google+ Vice President of Engineering Dave Besbris said he was "thrilled" about the deal.

Wroblewski, Yahoo's former chief design architect and an entrepreneur in residence at the venture capital firm Benchmark, also wrote the book "Mobile First," which is now an oft-repeated Silicon Valley mantra.

The acquisition seems in contrast to some of Google's recent moves surrounding the social network. Other shifts relating to Google+ have been around extending the social network's features beyond its closed walls. For example, Hangouts, Google's videoconferencing service, in July was added to the company's suite of enterprise software. The company will also reportedly break out popular photo features of Google+ to become a standalone brand.

It's unclear what exactly Wroblewski and his team will work on with Google+, but other newer social networks have recently integrated polling features. In August, the mobile app Secret, which lets users anonymously post to the service, added polls as well.