Renting may be a cheaper option for college students and parents in a time of tight finances, with college tuition and expenses a burden for many families. Amazon.com launched Kindle textbook rentals, promising tens of thousands of textbooks at discounts of as much as 80 percent less than purchase price on Monday.

Students tell us that they enjoy the low prices we offer on new and used print textbooks. Now we're excited to offer students an option to rent Kindle textbooks and only pay for the time they need - with savings up to 80 percent off the print list price on a 30-day rental, said Dave Limp, vice president, Amazon Kindle, in a press release.

Rented textbooks can be accessed across other devices - cell phone applications - as well, such as the Kindle smartphone app.

Students can rent textbooks for up to 360 days, and will only pay for the specific time they need a book, the company said. Rental times can also be extended day by day. Amazon's entry, which comes after rival Barnes & Noble's, arrives as the National Association of College Stores estimates that U.S. college stores posted $10.25 billion in sales for the 2009-2010 fiscal year with each student spending $745 on average.

Normally, when you sell your print textbook at the end of the semester you lose all the margin notes and highlights you made as you were studying, Limp said. We're extending our Whispersync technology so that you get to keep and access all of your notes and highlighted content in the Amazon Cloud, available anytime, anywhere-even after a rental expires. If you choose to rent again or buy at a later time, your notes will be there just as you left them, perfectly Whispersynced.

Amazon said tens of thousands of textbooks will be available for the 2011 school year.

For example, an intermediate accounting book sells for $109.20 on the Kindle, but can be rented starting at $38.29. An organic chemistry book sells from $98.80 on the Kindle, but can be rented for $42.41.

In August 2010, book retailer Barnes & Noble unveiled a Web-based textbook rental service and in July 2010, Borders also announced an online textbook marketplace, though the company is currently embroiled in a bankruptcy proceeding.