Pengi - 8:38 am on Oct 18, 2006 (gmt 0)

I'm sure it's been covered before, but the referral button is not an Ad and, as I understand it, payment is for the action (downloading from the subsequent link) rather than the initial click on the referral button.

If you are in any doubt, check with Google, but I think:
a) It would be accectable to provide instructions and explanations such as - "click on the referral button to download products" provided everything is made clear to the visitor, and the payment requires some subsequent action following the initial click.
b) It would not be acceptable to mislead people to send them to your page with the referral button.