Someone who signed up as "Fox289" is Instagram user number 50 million. According to "="" target="_blank" rel="noopener noreferrer nofollow">Gramfeed, he or she has uploaded one photo and has six followers.
Instagram was initially released on October 6, 2010. In December 2010, Instagram had 1 million registered users. In June 2011, Instagram announced it had 5 million users, and it passed 10 million in September 2011. Instagram started 2012 with some 15 million users. Last month, it passed 30 million users, and then 40 million users, and now 50 million users. This growth rate, while astonishing, can't go on forever.
Since Facebook is going public, it will soon have to start disclosing Instagram's numbers. I will be particularly interested in what percentage of Instagram accounts are false or duplicate. Something tells me the number won't be as high as the percentage on Facebook: 5 to 6 percent, or some 50 million users.