Gets rid of your used books is a good idea to clean the clutter and to make some extra money. Your used textbooks might be useful for somebody else and you can sell back textbooks online to them. However, when you are in college, your aim is to get the maximum penny on used books by selling textbooks. There are hundreds of online stores to sell textbooks for a good price compared to the college store.
We listed a couple of textbook sites here to sell textbooks online. You can see their process fees and other commission rates to take a quick decision and pick the right site to sell textbooks online.
Sell Books on Amazon
The books you wish to sell must be in at least good condition and the ISBN must exactly match what is displayed on the website. You can trade in books or you can sell it on amazon.com with free shipping to amazon.com. You will get payback up to 80% with the Amazon gift card. 
Link:Â Books on Amazon
Sell Books on half.com
At Half.com one of the main online sites to sell a textbook for a good price. With half.com, there are no start-up, listing, or monthly fees. Half.com is making money based on your used book sales. Half.com takes a commission off the selling price at the time of textbook sale. Commissions for the sold books are calculated as a percentage of the selling price of the item only. 
The shipping cost is not added to the selling price. (Selling price of item sold -commission + shipping reimbursement). Selling price and (Commission rates) are as follows: $0.75 – $50.00 (15.0%), $50.01 – $100.00 (12.5%), $100.01 – $250.00 (10.0%), $250.01 – $500.00 (7.5%), $500.00 above (5%). Half.com pay sellers by direct deposit twice a month or whatever your seller account balance is on the pay period ending date into your checking account approximately seven business days after the end of the period.
Link:Â half.com
Sell Book on Barns&Noble
To sell textbooks on Barnes&Noble, first, you have to get a quote from Barns and Nobles. Next, you have to get a quote for a textbook, click on Sell Your Used Textbooks. Then locate the ISBN number on the back of the book you want to sell and enter it above. Click on the button, “Get A Quote,” to see how much Barnes & Noble will pay you for your book. If you agree on the price, Barnes & Noble will provide you with a return label so you can send the book for free. 
Once Barnes & Noble receives your textbook, they will send you a check for the total sale if your book is in an acceptable condition. You must have at least $10.00 worth of books to sell in order to participate. A price quote is based on future demand for the book and current stock availability. You will get paid back in the form of Check, that normally arrives within 2-3 weeks from the time Barnes & Noble receives your package.
Link:Â Barns & Noble
Sell Book on Alibris
Alibris offers two types of accounts to sell used books. Alibris Basic accounts for those who are listing fewer than 1,000 items monthly. There has a Sign-up fee & annual fee of $19.99 and you have to pay $1.00 per retail item sold. The additional commissions include a 15% commission (minimum of $0.50) on any item. But you’ll never pay more than $60 per item in commission. 
Alibris Gold is good for those who are selling more than 1000 items per month. There has a sign-up fee & annual fee of $19.99. Here are the fees for Average listings per month (Flat monthly fee). 0–2000 ($20.00), 2,001–20,000 ($35.00), 20,001–50,000 ($70.00), 50,001–500,000 ($140.00), 500,001 and above ($400.00). The additional commissions include15% commission (minimum of $0.50) on any item. But you’ll never pay more than $60 per item in commissions.
Link:Â Alibris
Sell Book on Powells
Powells offer to sell back textbooks in three steps. Enter each book’s ISBN in the text box below and click “Sell these books”. If you like what Powells’ offer, you’ll just need to pack and ship the books to Powells’ warehouse in Portland, Oregon. Once they arrive, Powells will look them over and issue payment in your choice of online credit or payment through PayPal. 
Powells pay for Media-mail shipping within the U.S. Here you don’t need to wait until you sell back textbooks. Powell will directly buy your books. They will pay you by Powells Virtual Credit (sometimes referred to as “trade”) is credit that place directly in your Powells.com account. You can use this credit to pay any purchase made on Powells.com. Powells can automatically issue funds to your PayPal account. No worries about any other fees, monthly fees, etc.
Link:Â Powells
Sell Book on Ecampus
Ecampus is also buy back textbooks directly from you. You have to enter ISBN’s of any books you want to sell at a time and click “Search”. Ecampus will tell you if they can buy your books and how much pay for your books. Each quote is good for 7 business days. Once you accept the Ecampus offer, you will be required to provide your shipping address and an email address. 
Ecampus pay for shipping. At checkout, we provide you a link to a postage-paid mailing label. ECampus send you a check once they receive your books and verify that they meet Ecampus standards. Remember, unacceptable books will not be returned. Payment for buybacks will be sent to the address you have listed. The check will be made out to the name listed on the Full Name line of the shipping address.
Link:Â Ecampus
Related: How to Convert Ebook to Audiobook and Listen on iPhone?
Sell Book on Valorebooks
ValoreBooks.com offers free shipping on all sell back textbook orders, including textbooks. After you view the prices for your textbook, ValoreBooks.com will provide a prepaid shipping label so you can ship it for free. 
ValoreBooks.com offers two payment options when you sell your textbook back. You can select a standard check in the mail, or if you would like your payment expedited, you may select the PayPal payment option.
Link:Â Valorebooks
Online Book Stores to Sell Used Textbooks
Each textbook site differs based on their selling policy, monthly fee, and a sales commission of old books. A couple of them offers to post the item on their site for a monthly fee and commission for sales. There are sites offering to buy books directly from you without any additional commission or charges.
Most of these online bookstores are offering free shipping to send your textbooks to their facility or to the buyer. So the real catch is that to get maximum money for your used textbooks after you paid these commission and other charges.
If you want to explore more with the other online bookstores to sell back textbooks at a good price there are a couple of more sites you can go through. The online bookstores like  Biblio, BigWords, BlueRectangle, BookByte etc., are good for selling textbooks and you can get good money for your used textbooks.