From eMarketer comes statistical proof that a brand’s Facebook’s followers are more likely to buy or recommend that brand.
It seems pretty self explanatory especially when you consider the reasons why people become fans of brands on Facebook. If I am a fan of a brand, of course I am more likely to buy that brand.
The magic happens when you prove the first graph across users who aren’t self-identified fans – so if you can make me become a fan of your Doohickey widget fan page, I become (either immediately or over time) more likely to buy your Doohickey widget. Then this stuff becomes very easy…until the next wave of communication comes along.
More interesting info here: Social Fans More Likely to Buy – eMarketer.