If you're anything like me, you hate opening your mailbox to see a whole pile of junk mail waiting for you. Credit Card offers (more on those in part 2 of this series ), fake checks from mortgage firms, endless reams of useless coupons and, of course, the trusty 1lb envelope of garbage from ValPak. But a friend recently told me of a hidden gem inside the ValPak envelope. A gem that's worth at least $20.

The voucher that's like Wonka's golden ticket.

Inside ValPak envelopes (depending on your zip code) is a voucher from Northwest Airlines. It looks something like the picture below (I apologize for the poor quality, it's the best pic I could find anywhere on the web).

Now, what this voucher does is give the redeemer anywhere from $25 to $100 off of a Northwest Airlines flight. Great, if you happen to be in the market for a flight. If you're not, which is probably the case, you'll trash it. But using the mighty reach of eBay you can find hundreds of people who desperately want to save cash on a flight. And that means quick money for the smart eBayer.

Making the quick buck(s).

All you have to do is list your Northwest Airlines voucher on eBay. As you can see, completed listings (for eBay novices, those green prices are the final SOLD price for the item) are averaging $20-$25.

That's cold, hard cash for a voucher that was sent to you free in the mail. List the item for a starting price of around $18.99 and give FREE shipping (it's just the cost of a stamp anyway). You may also want to do a Buy It Now option for $19.99. It's all up to you.

Get vouchers from friends, make even more money.

Most people will be more than happy to give you their ValPak envelopes, if they haven't already dumped them in the garbage. You could get 5 or 6 NWA vouchers and sell them in seperate auctions, or list them as "5 available" in one auction. Either way, that's at least $100 lovely dollars from something that used to be a pain in your butt.

Now, prepare for something you've never experienced before in your life. Get ready to be happy to see junk mail in your mail box. Next time, starting the Junk Mail war.