Obviously you can't twist anyone's arm to do anything, but communication is the key.
Not only through PSA mailer, but through personal e-mails and skype if available.
the more people hear from you, in all forms of communication, the more they will get to know you as a person and will begin to trust what you say.
Also your contests have to be doable and the reward should fit the action.
Communicate, communicate, communicate, this is the way to their hearts and minds!
