Since they operate independently and likely have their own cash pile for stuff like this, the legal entity making the purchase is actually Oculus. Same with like Nest/Google AFAIK.
I wondered the same thing about Nest/Google the other day.
It could also be an abstraction on the part of Google/Facebook to hide their associations with the brand, to avoid brand reputation damage of some sort.
Facebook is taking this holding-company approach to WhatsApp, Instagram and Oculus. Unilever, P&G and Nestle should be wary of another holding company controlling their customer channel, especially after the Axciom partnership which gives Facebook access to the _offline_ purchases of Facebook customers. The consumer goods companies should fund new social networks, to diversify their online reach.
"Audience Operating System .. allows advertisers to tie together your "digital persona" even if you've changed your name due to marriage, the use of a nickname, or because you sometimes use a middle name. It also figures out whether someone who has moved addresses or changed phone numbers is the same person or not."