From the Become Affiliates Website:
How does it work? It couldn't be simpler! We've streamlined our entire affiliate process to ensure ease of use, while still maintaining extremely accurate affiliate tracking. The process is as follows: Visitor clicks on an affiliate link on your site or in an email. The visitors IP is logged and a cookie is placed in their browser for tracking purposes. The visitor browses our site, and may decide to order. If the player deposit (the deposit need not be placed during the same browser session--cookies and IPs are stored indefinitely), the deposit will be registered as a sale for you. We will review and approve the sale. You will receive commission payouts. That's it! You send us business, we send you money!