Did you use it on a website or blog of yours or did you promote it other ways? I'm just curious as to how well it would work on a site itself.
I used to own a baseball forum, what I did was I targeted my eBay ads per block you set up. You can say this ad block show auctions using the words "Baseball Cards" on another add blocked I would show "Baseball Balls and bats" another will be "Baseball t-shirts"
So members of my forums will see Baseball cards, balls, bats, shirts for sale on eBay. The ads were so pin-point perfect to the forums interest. The auctions change daily, so it's never displaying the same items over and over again. Some of these items can sell for a lot of money and if you're making 6% of the sale or whatever it is now, it can be a big sum of money, plus whatever other shopping they do on eBay.
Well that's pretty creative. I wonder how many other people have gotten that idea and tried it out. If you had a lot of money to use you could make a real nice profit I bet.
In the gold/silver communities this was a big deal, everyone did it. You'll see AMEX come out with but this "Gold Bar" at spot offers. If you know anything about gold and silver, you can hardly ever buy anything at spot price, you always pay a premium to spot. eBay use to toss the 5x rewards out which is (10% back on the purchase price) + 1.5% back by paying with your credit card another 6% back with the affiliate program. Paying 17.5% less then spot price.
When you go to sell Precious metals, if it's in bullion form like a bar or coin, local dealers will pay you close to spot, spot, or even over spot depending on the item. Keep in mind, these dealers have to pay a premium also, no one sells under spot (Why would they?)
So you'll order 20 coins from AMEX on those special sales day, head to your local dealer and sell them 20 of your old coins yours replacing. And keep the 17% (20 ounces x 1300 x .17) = $4400 profit in a 20 coin transaction. You're income was limited by your bankroll.
Since the price of Precious Metals changes all the time up/down, you have to have inventory on hand in order to secure the profit. You can't wait the 1/2 weeks for delivery, the price can move to wipe out your gains or you can make a ton more. I take the no risk approach.
Then eBay got a little smarter, they removed the Ebay bucks rewards from "Bullion Coins" category. But you can still find coins listed in other categories, etc. Now, since the ebay/paypal split, I haven't gotten a 5x Reward, just the measly 2% ebay bucks.
Anyway, it's good to be well versed in several areas, so you can apply everything you learn across the board and take advantage of opportunity when you see it. No one really comes out and spells things out like this for people, until it's no longer viable.