This paper introduces an analytical model for the Follow-Me Cloud (FMC) concept whereby service mobility is enabled across data centers following the mobility of a mobile user. Given a network and cloud setup and a mobility pattern of a mobile user, the proposed analytical model provides the performance of the FMC concept related to: (i) the user experience with the service (such as: UE average distance from the optimal DC, average end-to-end delay, service disruption duration); and (ii) to the cloud/mobile operator (such as the service migration cost). Obtained results are encouraging. They confirm the advantage of the FMC concept, but stress the need for careful consideration when triggering the service migration.