Is the “buy” button on Facebook available to all, or only to those sharing the fact that they’ve bought from Amazon?

http://ift.tt/1iZHv9S

Is the Facebook “buy” button implemented only for buyers from Amazon sharing their newly bought products – I ask as I saw “buy from amazon” on sharing to Facebook after buying product from Amazon – or is it also for direct sellers? Can you weblink its screen shot?

Post and answer: Is the “buy” button on Facebook available to all, or only to those sharing the fact that they’ve bought from Amazon?