<human>:  Why did the price of a Kindle go up from $99 to $199?
<bot>: The price of a Kindle went up because the price of a paperback went down. A Kindle is a portable electronic device that allows you to read books, newspapers, magazines, and other digital content on a screen. The Kindle uses a special electronic ink display technology, which is similar to the one used in the Amazon Kindle e-reader. The Kindle has been on the market since 2007.