Social Network Analysis has been one of the hottest topics among data mining scientists in the last 5 years. Meanwhile, more recently, companies, especially in Telco, have progressively started using these techniques to improve their predictive models. Through a few case studies, I will present the questions that SNA can address, the methodology we have used and the results which the companies obtained. I will then present other applications (in retail and social network sites), currently being deployed, with the scientific issues they raise.