Cookies and Sales and other affiliates

Cant understand :(

[blue_eagle]

Here is the scenerion I don't understand from affiliate programs and it always confuses me.

For example, an affilate program offering 30 day cookie referal. Customer clicks A's aff link and goes to sale.com but doesn't purchase that date. After a week same customer clicks on B's aff link and goes to sale.com but doesn't purchase.
Third week same customer clicks on C's aff link and goes to sale.com and PURCHASES.

Soooo, who get's the comission? A, B, or C?

IT always confuses me and I am very corious about this. I would really appreciate if anybody can help me out.

Thanks in advance.

[blue_eagle]

sorry for posting to a wrong forum. Please move it.. :(

[deejay]

C.

General rule is last affiliate to refer gets the sale.