When it comes to the key metric of average revenue per user (ARPU), Snap still has some way to go. Having posted large losses on equally large revenue in 2016, the about-to-go-public social media firm is yet to prove it can sustain significant user growth and convert it into all-important profit. Like Facebook, Snap is very much reliant on ad revenue generated from its users and in Q4 2016, global ARPU was $1.05. For context, Facebook was pulling in $1.21 (13% more) in the three months leading up to its IPO and now boasts a global average of $4.83. With user growth slowing, Snap may need to rely on an equally impressive increase in ARPU if it is to survive.