아마존pay with checking account 해보신분 이게 뭔지요?안전 한건가요?해석요망

물건 구입후 결제 하려는데 이런 문구가 나타나네요.
정확이 무슨 내용인지 안전 한지 알고 싶어요.

1.500불 추첨이 꼭 된다는것인지
2.추첨에 될수도 있다는 것인지

3.체킹 어카운트 알려줘도 안전 한지 알고 싶어요.

if you pay for this order using the “pay with checking account” method, you’ll automatically be entered into this month’s drawing for a $500 Amazon.com Gift Certificate/Card.
Learn more & Enter to Win or

Learn More About the Sweepstakes.
Make a purchase at Amazon.com before August 7, 2008
Pay for your order with your checking account.
You’ll be automatically entered into our monthly drawing to win a $500 Amazon.com Gift Certificate/Card. No purchase or payment of any kind is necessary to enter or win this sweepstakes.
Once a month, a winner will be selected from a random drawing of all eligible entries collected during that month. The winner will be contacted by phone.
It’s that simple.

To sign up and be eligible to win: Pay Directly by Checking Account