This feature allows Nexternal merchants to offer immediate reward to shoppers for promoting them on Facebook. When the shopper likes a product in the merchant’s online store, the “Like” gets automatically posted onto the shopper’s Facebook Wall and in their friends’ "newsfeeds" with a picture (if available) and short description of the product. The merchant then automatically gives the shopper an instant discount for purchasing that product.
Activation: Settings / Compatible Software - Edit / Social Networking. Click on "Preferences". You have some button style options available here. (Read the appropriate question marks for additional guidance)
It is highly advisable to in the Admin ID box (here's info about that http://ecommerce-blog.nexternal.com/what-is-a-facebook-admin-id-why-should-i-care/ )and your Sharing Discount. This can be a flat fee, or percentage. Click Submit at the bottom of the page. Back on your main page (Settings / Compatible Software - Edit and scroll down to Social Networking), also be sure to click "Facebook" and click finish.
If you want to override the discount on any product, or remove it completely from any product, edit the product, click next and you'll see the "Product Overrides" area at the top of the product's page 2. You'll see another Sharing Discount box there. Anything you put here will override your overall setting for that product. Click next or finish to save.