Update: Here are some good investment books that you can get for free or cheap with this discount code. Check out the top-selling Kindle e-textbooks for ideas, but I like The Ivy Portfolio and the classic Common Stocks and Uncommon Profits. Thanks to reader Max for the tip.
Amazon.com is offering another $10 of free credit towards Kindle e-Textbooks with the code ETXTBOOK. Additional directions and a place to enter your code at this link. I don’t believe you actually need a Kindle to use these electronic textbooks, as there is a Kindle app for PC, Mac, iPhone, and Android phones as well. You must use it by 11:59 p.m. PST on January 9, 2012. I got this for an Amazon Student account, but it should work for everyone.
Are electronic textbooks much cheaper than paper textbooks after taking into account selling the used book back? I have no idea.