Infin8ty: That's the difference between PRNG's and raw speed, although if you knew the PR algorithm, then you could manipulate it.
Ungunbu: naaah
when you click buy a checkout link is generated for you and you are redirected -- you can't do anything about it imho -- the link is saved in the db
Theoretically, the PRNG after a modulus will result in a Boolean value that determines whether it's free or not; if you estimate the rate at which people access the site and know the PR algorithm, one could greatly increase their chances for getting a free game. It still wouldn't be 100% as there is an estimation element, but if one knew the PR algorithm, it would be easier.
Also, the source code would be great as well.... :)
(I don't know the PR algorithm used, they tend to be absurdly complicated and vary between different OS's, and sometimes hardware.)