Launched in 2010, Instagram is an online photo sharing service that has taken the world by storm. By its third month of existence, it had gained its first million registered users. Today, it boasts millions of users with hundreds of millions of photos uploaded. The company was purchased by Facebook for around a billion dollars in cash and stock in 2012.
But there are plenty of other photo sharing services online, many of which existed long before Instagram. What makes it different? There are a few things: