Many marketers have strong CRM databases that they use to target direct mail or email offers. A growing number of them also have robust Facebook or Twitter followings. But few marketers have figured out how to marry the two. The idea of one grand database of consumer information, interests and intentions is the holy grail for managing marketer-customer relationships, and the idea of using social data from a network like Facebook to get there is hugely appealing. But when it comes to integrating this kind of social data, it's easier said than done.