Here's how it was described to me (almost copy/paste):
Go to
www.bing.com
Look for link in upper right corner "sign in"
click on that link and sign up for a bing.com acct (very easy and free)
When complete, go to Ebay, click on the MacBook Pro item and click on "watch this item". This puts the MacBook Pro in your watched items (if it is already in your watched items, you can skip this step).
Go back to
www.bing.com
Type in MacBook Pro
Go to one of the very first links you see, it will say, "Buy MacBook Pro ... you may get 8% off w/ PayPal if eligible"
Click on that link
That will bring you back to Ebay
Go to the links on the top right side that say, "Buy" "Sell" "My Ebay" "Community" "Help"
Click on "My Ebay"
This will bring up your watched items, including the MacBook Pro.
Click on the MacBook Pro and click on "Buy it now" (this will not complete the transaction, so don't worry ... you still need to confirm the purchase)
THIS IS IMPORTANT!!!
Look for a little green sign saying "Microsoft Cashback 8% -- US (approx $72)?
That will let you know it has worked properly.
Then complete the purchase.
You will need to pay the full amount and you will receive a cashback to your paypal acct in 60 days from Microsoft Bing.