I'm using PHP & MySQL to limit access of downloads to unregistered users.
The only options I see to do this are cookies and/or IP address.
Cookies is not a good solution, seeing as it's important that a user can't reset their download count by deleting their cookies - as the idea is that they pay if their usage is above a certain level.
That leaves me with restricting the access by recording the IP address in PHP and inserting it into the MySQL database. The problem with this traditionally is that some people are on dynamic/shared IPs, and so the count will mean nothing to them, and could even stop other potential customers from having their free downloads.
But then again, virtually all of my sales are from Western countries, and it seems that most people in the West are now on a static IP address... is this correct?
What would be the best solution for this dilemma? Any thoughts?