The MAU metric has a value as Twitter earned $1.79 from each user in the last quarter. Financial models, which are used by many to guide investment decisions, u

The MAU metric has a value as Twitter earned $1.79 from each user in the last quarter. Financial models, which are used by many to guide investment decisions, use the expected MAU as one input used when modeling the expected future earnings. When MAU deviates from these models it causes these projections to change, causing the perceived worth of the company to be re-evaluated. If the perceived value of the company is now less than the market cap implied by the current share price then you’ll see downward pressure on the price. Twitter and Facebook are largely measured by their growth. If that slows you’ll see investors head for the exits.