"Pay per share" button

Hi there, I would like a very simple Button places on my website(s) - I am looking for a "pay per share" function. On pressing the button, the user has "liked" my page on Facebook and a DOWNLOAD OF A PDF DOCUMENT starts after he has clicked the button. In other words he has "paid" for the PDF download by "liking" me on Facebook. To break it down: The button would say "Pay Per Facebook Share". 1. The user clicks the button. 2. My Facebook page is "liked" and shared on the user's page with a short message saying "I just downloaded this PDF at [login to view URL]". 3. A PDF book is available to the user AFTER he has clicked the button, and "paid" for the PDF with a Facebook share. I want a simple piece of code I can re-use on several different sites. Thanks! /Russ