Kindle vs. iPad : The Wealthier, Educated vs. The Younger ?

As per Nielsen report, Kindle owners are more wealthier, older and educated compared to younger and majorly male  iPad owners.

Source : Nielsen

Amazon Buy-Back Offer Pricing

If you haven't noticed this "Do The Math" widget already, Amazon appears to be offering a Textbook Buyback store where you can sell your books back to Amazon. Amazon is including the price at which a particular book can be bought back and showing the effective price you may have to pay if you just want to read it once and return to the store.

Quite a saver.