The Payvment app couples PayPal’s API with Payvment's shopping cart, allowing you to sell products directly on your Facebook Page… for free! This is a comprehensive app which allows you to add products and assign those products to a category. Payvment's app allows you to upload photos, list terms of service, provides shipping options, offer coupons and much much more. Your customers can shop for products like they would from any other e-commerce site, right on Facebook.
One of the coolest features of the Payvment app is that it is integrated with all other Payvment stores, both on and off Facebook. If a user adds a product to their cart from your store, and later goes to check-out after shopping at another Payvment store, your item will still be in that user's cart.
Payvment recently announced the ability for merchants to import entire inventory catalogs from CSV and a number of other formats.
Payvment does offer an admin panel, but there appears to be no analytics for the app.