ebay bucks accounts were assigned randomly, so you can't sign up yet, unless you got lucky like Beckles.

First, get a Mr. Rebates account and Bing account. This is my referral link:Mr. Rebates. There are other links, including a conga in SPAM, I believe.

Now, for each purchase, here's what I do. If you want two cards, you have to do this twice - Bing resets after each purchase.
1. Sign into ebay, if needed.
2. Go to bing.com and sign into bing. Use their search engine. I usually enter "gold coin", but I just tried "costco cash card", which also worked. At the top of the results will be a sponsored link, near a gold coin with dollar sign. Click on that link.
3. You'll go to ebay. If you were successful, there should be a green "Microsoft cashback" logo at the top of your ebay screen. If not, try again in Bing.
4. Go to Mr. Rebates. Sign in, if needed. Type in ebay in the search engine on the front page. Store results for ebay will pop up. Click on the link. Mr. Rebates will give you a popup window. You'll go back to ebay, and your green logo should still be there.
5. Do your shopping - don't close the browser or anything. You want a Buy It Now that takes Paypal to get the Bing money. Of course, you can use a credit card through Paypal - go starpoints!

When you make your payment, the Bing notice will come up within a few minutes. Mr Rebates takes one or two days to send you an email. Bing and Mr Rebates keep track of your rebates. Bing releases them in 60 days; Mr Rebates, 90 days.