Are people allowed to advertise on private websites?

[teeny-tinyarm663]

My ex-landlord is displaying ads on the facebook page of my college.
I mean, it's a site designed for updates from the college and not for ads unless it relates to the college.
He puts walls posts advertising his rental property.

[Quizzard]

No, FACEBOOK places the ads where their software thinks is best. It is by no means private, it belongs to Facebook

[Caoedhen]

He can post anything he wants until either the school or Facebook decide they don't want him to do so. Facebook won't care since he is not advertising anything illegal, and apparently the school doesn't mind either.