Got a lot of customers and contacts that aren’t fans of your page yet? Well now you can invite them right through facebook. You access it through build audience on your admin panel.
Select your email platform from the list:
If it’s not listed, use “other tools” and upload your contact file.
Once this is done you will have the option who to send invites to. For those already on facebook they will receive a notification message recommending they “like” the page. And if they are not on facebook an email will be sent to them inviting them to become a fan. You’ll see this preview before you proceed and will need to check the box indicating you have permissions to email these contacts.
For complete details check out the facebook help center.