Unfortunately there's a hard cap on the number of potential users in the world. There's about 7 billion people in the world right now, even if we're generous an

Unfortunately there's a hard cap on the number of potential users in the world. There's about 7 billion people in the world right now, even if we're generous and suggest that 50% of the population are potential users you're limited to a 3 billionish maximum. They currently claim over 500 million active users, which means they're already at 1/6 of their maximum. Furthermore, the law of diminishing returns suggests that their growth will slow as they get close to their population limit. So unless they can figure out how to monetize those users in some significant way I can't see the potential for revenue being close to what the current evaluations are suggesting.