Facebook on Monday said it is closing the polls on "an experiment with democracy" that let members of the social network vote on proposed policy changes.

A referendum to strip Facebook users of the power to endorse or reject policy changes through popular vote was opposed by 87 percent of the 668,125 members who cast ballots but not enough people voted to make the results binding.

Since fewer than 30 percent of Facebook's one billion users voted, the California-based firm exercised its option to go forward with a plan to eliminate the voting structure and integrate Instagram data for ad purposes.

"Facebook is likely to make an announcement soon about the vote's results and when the new versions of its Statement of Rights and Responsibilities and Data Use Policy will go into effect," the social network said in a blog post.

"Beyond the end of Facebook's experiment with democracy, the most interesting outcome of the vote is that Facebook will be able to intermingle data with its affiliates including Instagram."

Facebook bought smartphone-picture sharing service Instagram early this year in a cash and stock deal valued at a billion dollars at the time.

A week ago, Facebook asked its members to vote on an overhaul of privacy and other policies in what on Monday became the last binding referendum of its kind at the huge social network.

The social media giant, which has drawn fresh fire from privacy activists for the proposed changes on how it manages users' data, said the poll would be binding only if it gets responses from 30 percent of members -- or 300 million people.

The changes end the voting process, and also would permit sharing of information with its newly acquired photo-sharing service, Instagram.

Additionally, the changes would make it easier for advertisers and others to send messages on Facebook, limiting users' control, according to privacy rights groups.

Activists have raised a ruckus, saying the new policies, if implemented, could violate some laws or Facebook's agreement with US regulators earlier this year after complaints from privacy groups.

Facebook said in a message to users last month that the vote system -- implemented in 2009 -- "resulted in a system that incentivized the quantity of comments over their quality."

Facebook's stock price tumbled after its hotly anticipated market debut in May at $38 a share, in part due to concerns over ad and revenue growth.

However, Facebook shares have rallied in recent weeks and were up slightly to $27.92 on Monday.