> Facebook runs a low-support model.
Not for large advertisers they don't. Here in Ireland for example their outsourced advertising support & soft-sales, a large part handled by Accenture, are huge. Possibly more numerous than the Facebook EU HQ here. I'm sure the case is similar elsewhere.
Keeping large offices running smoothly and in nice conditions takes an enormous amount of manual work, a lot of which other employees never see (much of cleaning/maintenance is done over weekends and at night).