1.5 billion photos are uploaded to Google+ each week

"Matt Cooke, product marketing manager for Google+, says that Google+ has 540 million monthly active users, 300 million of which view their Google+ content stream at some time during the month, while 1.5 billion photos are uploaded to the site every week. "Slowly but surely we are getting a feeling that there's a real momentum, but it is still early days and there are plenty of opportunities to grow and add new features and make them easier to use," he says."

Source:  The Guardian, 5th February 2014