The MVNO (Mobile Virtual Network Operator) business in Europe is maturing, with growing pressure on margins. To cope, MVNOs seek independence and flexibility which they can gain by advanced 4G access agnostic technology. This evolution is supported by three overlapping MVNO models: 4G "Full MVNO", Multi-MNO and "Always Best Connected", which are all enhanced by advanced Policy functions. The paper assesses these models against top ten MVNO success factors and argues that the "Full MVNO" model can provide independence from MNOs, that the Multi-MNO model allows flexible mix-n-match services for any taste, and the ABC (Always Best Connected) model gains in optimized costs. The paper also shows that 4G Policy enhances MVNO's ability to attract users by service variations, variable pricing and aligning user pricing with the suppliers' charging regimes.