To answer this question there are companies that have done different analysis and some say that the value of a fan on FB is 4 euros while others say 78 euros.
Now is the time to raise the question about how you can know the value the fan on FB.
In this case, you can use one formula created by the American company, Fanscape, called SRV (social relationship value) which allows to know the value economic of a fan for the company, which is also applicable to any type of business.
First highlight the relationship that exists between database of emails and social networks, since one of objectives to make a sustainable business is to teach the product to the customer, motivate you to buy it and keep you interested in order to get a loyalty.
There are market studies which say that an increase of 5% in customer loyalty can improve profitability by 65 %