What is the fine-grained topic of the following text: The research went on to conclude the value of a Facebook fan was $174, an increase of more than 25% since 2010, and urged brand marketers to try to get to grips on why Facebook users became a fan of the brand in the first place, as there may be far more effective and efficient strategies to gain the right kind of fan in a marketing sense - a regular spender. Only return the topic.
The value and marketing strategies of Facebook brand fans.