In recent years, Social Networking Sites (SNSs) have increasingly gained popularity. With the existence of hundreds of such sites, it is not uncommon to have users switching between them. Thus retaining existing users and attracting new users is crucial to the success of an SNS. This paper frames the described phenomenon as a "cyber migration". We enlist and adapt the push-pull-mooring framework developed in migration literature to enhance the understanding of factors influencing the switching intentions of SNS users. A survey study was conducted which manifested dissatisfaction with member policy and peer influence as two central factors, alongside other findings. We recommend SNS practitioners to be more sensitive to users’ reactions to the change in member policies. Meanwhile, how to utilize peer influences to maintain and develop membership deserves closer attention. The findings are believed to increase our understanding of an interesting Internet-enabled phenomenon, ...