While GM gave no specific reason for dropping Facebook ads, a source familiar with the automaker's plans said the company's marketing executives decided Facebook's ads had little impact on consumers.
While GM's decision could be an exception in the advertising world, it marked the first highly visible crack in the Facebook strategy, said Brian Wieser, Internet and media analyst at Pivotal Research Group.
Source: Reuters.com
My Take:
Facebook is about tech and games. Unless you annoyingly completely rebrand a whole website there will be almost no impact.