A business relationship that began in 2004 between Mark Zuckerberg and Kevin Systrom has ended in a marriage: Facebook has agreed to acquire mobile photo service Instagram for $1 billion. According to CEO Mark Zuckerberg, "This is an important milestone for Facebook because it's the first time we've ever acquired a product and company with so many users. We don't plan on doing many more of these, if any at all." Facebook also stated that the two services would remain separate. The Instagram acquisition was made just days after Instagram launched a massively popular Android app.