One hot topic at OpenWorld today was about building loyalty. One common measure is the Net Promoter Score (NPS). This measures the likelihood of customers to recommend your products compared with the likelihood that they will detract. It is primarily about intent.
One lesson learned is that you can move beyond a customer promoter rating to measure customer referral value (CRV). That is based on the combination of attitude and behavior -- actual buying and recommending is good. One strategy is to focus on customers who have a good attitude but could buy and recommend more. They are natural advocates, if you will nurture their loyalty.