> I remember when Facebook bought Instagram. Instagram had something like 13 employees. Why does Twitter need two orders of magnitude more?
Companies tend to hire more employees as long as the marginal benefit to doing so is greater than the marginal cost. Even minor improvements to a product like Twitter can boost revenue by millions. Reducing the headcount might not maximise their income.
There will be exceptions though. Valve does lot more than most video-game companies with far fewer employees.
A "video-game company" doesn't necessarily have to be a game developer, and being a distributer is enough. Consider how "music company" aptly applies to Spotify.
Companies tend to hire more employees as long as the marginal benefit to doing so is greater than the marginal cost. Even minor improvements to a product like Twitter can boost revenue by millions. Reducing the headcount might not maximise their income.
There will be exceptions though. Valve does lot more than most video-game companies with far fewer employees.