Amazon revealed sales of eBooks for its Kindle eReader are booming, the e-tailer says eBook sales grew 163 percent in the month of May and 207 percent year-to-date through May. The company also revealed that for every 100 hardcover books it has sold over the past month, it has sold 180 Kindle eBooks.
In a statement, Amazon says that, “over the past three months, for every 100 hardcover books Amazon.com has sold, it has sold 143 Kindle books. Over the past month, for every 100 hardcover books Amazon.com has sold, it has sold 180 Kindle books.”
That's impressive, especially considering it was only back in December that Amazon was celebrating Kindle books outselling the real thing on Christmas Day. Six months later, the shift has apparently become the norm.