If we stick with the comparison to TV shows the Amazon pricing model is like a season pass — you pay once and get all future episodes. Amazon also says that readers will be able to join in a discussion around the stories as they continue. The Serials announcement was made at Amazon's press conference today, where CEO Jeff Bezos also talked more broadly about the success of the Kindle Direct Publishing program. Of the top 100 Kindle books, Bezos said 27 are from KDP. He also noted that Amazon has created a new publishing format before, namely Kindle Singles, which was intended to fill in the gap between magazine articles and full-length books. There have now been 3.5 million Singles sold, he said.