The biggest category of external advertising was financial services, which represented 18% of the total on news sites.

FORBES: Depressing: News Sites Are Their Own Biggest Advertisers

It angered some members in the past when it introduced a new advertising system, called Beacon, which delivered adverts to users on external websites based on their Facebook profile and habits.

BBC: Facebook offers control to users

Because of this new world of information sharing and audience fragmentation, it is important that the messaging in advertising, media (in a PR domain), product packaging, internal and external memos, etc. be consistent.

FORBES: PR Is Dead