I work for an organization that offers advice on various aspects of business intelligence. In the past we have only offered our content as an on-line subscription service. However we're considering releasing our content in PDF format.
I was wondering whether there was a way of somehow securing the PDF's so that they cannot be transferred between different computers. Of course we could add a password to each PDF but that becomes difficult if we're selling 50+ per week. especially if we want these to be purchased directly off the website and we want to assign passwords on an individual basis.
What would be the best way of securing these PDF's?