Here’s the details of the credit from the Amazon Web site:
Get a $100 Credit
Order the PlayStation 3 160 GB and receive a $100 promotional credit toward the purchase of items shipped and sold by Amazon.com (certain exclusions apply, including Kindle books, MP3s, and video rentals and downloads). The promotional credit will be added directly to your Amazon.com account within two days after your order ships. Limit one per household. Offer valid when shipped and sold by Amazon.com. Amazon reserves the right to change or terminate this promotion at any time.