JFBConnect doesn't directly support Page Promotions in any way. There are a lot of terms and conditions on how promotions that collect any data from users must be run and we're currently not trying to target that ability.
With that said, JFBConnect does allow you to show your website within a Facebook Canvas Application area, like with our site:
apps.facebook.com/joomla-extensions
You can use that to have your own survey/promotion/coupon/etc run within a Facebook area, which can be easier to promote. You can even use the Canvas area to show your Facebook authentication button (from JFBConnect) and allow users to register on your site, and collect name, email and other profile information just like on your site.
I hope that explains some options and ideas, but if you have any other questions or feedback, please let us know!
Thanks,
Alex