Facebook crossed a significant milestone last month: On average, the service now sees more than one billion users every single day -- 1.01 billion, to be precise. Daily active users are up 17 per cent from last year, the company revealed Wednesday. Facebook made the announcement as part of its Q3 2015 earnings release, which pleased investors with some other big numbers: Facebook generated $4.5 billion in revenue in Q3 of 2015, compared to $3.2 billion during the same quarter a year ago. Facebook's adjusted net income was $896 million during Q3, compared to $806 million a year ago. Facebook's continued growth is largely driven by mobile: 894 million people used Facebook on their phones every single day in September. Mobile daily actives are up 27 per cent compared to last year. Altogether, Facebook now has 1.55 billion monthly active users, with 1.39 billion of those checking the site with their mobile devices. And Facebook is getting a lot better at monetizing all those mobile eyeballs: 78 per cent of Facebook's ad revenue is for mobile ads. A year ago, just 66 per cent of all ad revenue was generated on mobile. Zuckerberg said during the company's earnings call that these numbers were a testament to its mobile strategy. He also said that Facebook is seeing a lot of growth in video, highlighting two new numbers: Facebook now serves more than 8 billion videos every single day, which are being consumed by more than 500 million users. Asked about virtual reality, Zuckerberg said that it may take some time for consumers to buy headsets. For the first few years, Facebook expected virtual reality (VR) to develop as slowly as smart phones did in their early days, he said, adding that this will also influence the pace of VR content investments. "I don't expect that (to be a) a big industry for people to invest a huge amount in 2016," he said.