But how many accounts quit before generating any meaningful amount of data? Most of my GW1 friends quit before reaching 500 achievement points. And 30 TB is not that much anymore. Even if they would use premium class SSDs instead of HDDs, the costs would be neglibel in comparison to other expenses of the company.
Without insight into their infrastructure you can’t make such statements. 30 TB SSD on multiple fail-safe NetApps are pretty expensive. Never forget that our data are probably stored on multiple locations (2+ at least). You can’t compare your home HDD/SSD prices with those in professional environments.