I'm a little jealous of the Coinstar business model. They have machines that take cash money and give back 91% of it. That's a worse payback than a Las Vegas slot machine. Yet, people use Coinstar machines. Why? Because they don't want to stand at a cashier, counting through a fishbowl of coins.

Recently, self-checkout machines have provided a new path for wayward coins. Embarrased to hand a cashier 1,000 nickels? No problem. Bring them to IKEA, where you can feed them into the self-checkout coin slot and get their full value applied to your AKKROVE purchases.

In November, 2010, newer self-checkout machines showed up at Safeway grocery. These newer machines feature a coin-funnel, allowing users to deposit a handful of coins at once, just like the Coinstar!

This is the solution I was after. Now I can use my coins to buy groceries or other stuff at Safeway, instead of giving away 9.8% on a Coinstar machine.

However, a test was in order. Was there a way to exploit the self-checkout machine, gaming it to accept a surplus number of coins and give paper bills in return?

I concocted a plan. I would gather a bucket of loose change, then visit the Safeway self-checkout with a tiny purchase. What would happen if I tried to pay for a pack of gum with $32 in change? I was betting I would get the most efficient change in return, which in this case would be a twenty and a ten, or perhaps three ten dollar bills.

In no time I set my plan into action. I gathered a pint of change from my sock drawer and began trolling Safeway for their cheapest item. It was this packet of cherry Kool-Aid powder: 34 cents.

With my shopping done, I visited the self-checkout aisle #8. I scanned my cherry packet and hit "Finish and Pay". My total was 34¢. I grabbed a handful of coins and began filling the coin funnel. They whirred and clicked inside the box and my TOTAL PAID started showing up on the screen.

This was totally going to work!

But then! It was over. There was no Coinstar exploit.

Once I passed the total price of my purchase, the extra coins dropped right through the machine, into a hopper below.

Dammit! My scheme was foiled. I wouldn't be converting my coins to cash in the checkout lane. Looks like I'll have to buy groceries with my change.

That's fine, of course. Now I'll have a choice: Coinstar or Beerstar.