This is based on a comment I wrote on the Mashable post Why Instagram Was Worth $1 Billion to Facebook which has absolutely no explanation of why Instagram was worth $1 billion to Facebook.
How can you have a whole post about how Instagram was worth $1 Billion and have absolutely zero numbers in it? Yet that's what we're seeing all over the internet in the wake of Facebook's billion-dollar acquisition. Many people have explained why Facebook bought Instagram, but few have explained the valuation. Explanations for the purchase generally break down into these points: