Online mega-retailer Amazon.com has extended its trade-in program to include electronics products, the company announced yesterday. The program, which initially allowed exchanges of video games, movies, and textbooks for Amazon gift cards, now includes gadgets such as tablets (including the Apple iPad), smart phones, and digital cameras.

Unlike a buy-back program, such as those offered by Best Buy and Walmart (see our in-depth story on buy-backs at CRO for more information), Amazon's trade-in program requires no up-front fee and is not limited to products bought on Amazon.com; what's more, shipping is free.

To determine the value of an electronics device that you'd like to trade in, go to Amazon's trade-in page and search for the name of your item. The item's name must match Amazon's listing exactly, or it won't be accepted.

You then determine the condition--like new, good, or acceptable--of your item according to the category description listed with each product type. Each condition level has a different price associated with it, depending on the product. When Amazon receives your shipment, it has to agree with your description; if it doesn't, you can choose either to have your gadget returned or to receive a gift card at the value Amazon selects.

Once you've submitted your item electronically, you print out a shipping label that lets you send in your item (or multiple items) at no charge. And when Amazon approves the returned item's description, it deposits a gift card into your account at the agreed-upon amount.

Say you'd like to trade in a first-generation 16GB iPad, which sell for around $445 at Amazon currently. The three available trade-in values (depending on the tablet's condition) are $235, $200, and $162. It's possible you'd get more selling the iPad on your own--but this program would save you that hassle. And you save the up-front fee that a retail buy-back program would require.