Start by visiting Gazelle's homepage. Select the iPad from the product lineup, and indicate the iPad model you own, whether it has a cellular connection or Wi-Fi only, and your iPad's storage capacity. (If you don't know which iPad you own, it takes only a few moments to find out.)
Once you click through those questions, Gazelle will present you with three condition levels: Broken, Good, and Flawless. Choose the one that applies to your iPad, and Gazelle will tell you how much it will pay for your iPad. If Gazelle can't offer you any money for your old iPad -- for instance, it's a broken first-generation model -- the service won't take the device back, though it will refer you to information on recycling your iPad.
Glyde isn't a true buyback service in the same way that Gazelle is. Instead, it's a marketplace of sorts where you can easily sell your usable, nonbroken electronics. If Glyde determines that your iPad is too damaged to sell, Glyde will buy it from you outright and repair it to resell later. If your iPad has no resale value, Glyde will refer you to Glyde Donate, where you can donate your broken gear to the charity or nonprofit of your choosing.
To use Glyde, start at its home page, and select Sell iPads. On the next page, choose your iPad model from the list. At this point, Glyde will ask about whether you have a model with cellular connectivity or Wi-Fi, your iPad's storage capacity, and its bezel color (if applicable).
Once you answer those questions, press the Next button, and Glyde will request more details on the condition of your iPad to get a better sense of its fair market value. After you submit your answers, Glyde will give an estimate of how much your iPad is worth and will offer to buy it back outright or to list it for you to sell.
If your iPad is in good enough shape to list on Glyde, the service will give you the option to adjust your asking price. By default it will show the Market Price -- the standard going rate for your tablet -- but you can adjust that up or down as you choose. You won't get cash up front, though, and Glyde will take a transaction fee and shipping fee out of your asking price.
Aside from the services above, you also have a couple of old standbys at your disposal: eBay and Craigslist. eBay lets you set a Buy It Now price or a starting price for auction, and at Craigslist you get to set the price yourself. If you choose to sell through either of these sites, you'll want to keep a few tips in mind.
Don't accept personal checks: A less-than-honest buyer could easily write a bad check, leaving you in the lurch should it bounce. Instead, either use a service such as PayPal or request a cashier's check or money order. This way, you can guarantee that you'll get paid.
Be honest: Disclose any damage to the iPad, and mention if anything is missing. Being up-front now will prevent hassles later.
Take lots of good photos: You'll want to provide plenty of photos that show your iPad's condition. Make sure you have good lighting, and try to take the photos on a clean, uncluttered desktop.
Don't make your buyer wait: Ship the iPad as soon as you can after you receive payment, and provide the buyer with a tracking number if possible so that they can get a better idea of when to expect it.