Facebook with their hundreds of millions of users, can pretty much do whatever they want and they've now started testing a new premium ad offering that allows pages to post a coupon to their fans and then use that post as an ad unit on the Facebook homepage.

Users who notice the ad, or the page post, can click "Get Coupon." From here, it can be posted to a user's Wall, they'll then receive an e-mail from Facebook with the coupon and an option to share it with friends.

Facebook said that pages who are part of the limited test can offer discounts that customers can either redeem in-store or online. This new venture from Facebook is different to their Check-In Deals, which is a self-serve promotional tool that allows businesses to offer coupons to people who visit a location and check-in with Facebook.

Facebook Check-In Deals are also only available via mobile. Facebook says:

We think this test is complementary to the other products we offer businesses and we hope to learn more about how this might work for both merchants and customers.