Share 'mailing lists'

How do you let peole who read and enjoyed old issues of your zine know when you finish a new one? I just have a Facebook group which I use to mass-message everyone when I finish a zine or when I'm tabling at a fair or things like that. The thing is that 90% of the people in the group are friends of mine and I've gotten rid of a lot of zines at fairs and through distros and leaving them at libra…