Scale is more important in the social media world than it is in many other corners of technology. A thriving social media site needs a wide user base, ideally one that's growing continually. Social ...

Roblox had an amazing second quarter, with impressive growth in users and paying users. However, the strength was driven by so-called viral hits, which could lead to unevenness in future growth.

All things being equal, more users mean greater engagement and -- critically -- more revenue. Sure enough, Roblox's top line has expanded thanks to that widening user base. The platform's in-game ...