Latest researches got a really impressive results. The statistics are showing that in 2016, more than 500 million of people are using Instagram each day. Just so you know, facebook currently has 1.6 billion active monthly users which is a good number to make comparisons with them both.

More info about the research can be found here: http://www.statista.com/statistics/253577/number-of-monthly-active-instagram-users/