Amazon reported that net sales were up 29 percent in the second quarter of 2012, totaling $12.83 billion. However, they missed Wall Street estimates of $12.9 billion in sales.

The company noted that Kindle Direct Publishing authors had scored 20 spots on Amazon’s list of the top 100 bestselling Kindle titles. The quarter also included an estimated loss of $65 million as the company acquired Kiva Systems.

Here’s more from the release, looking ahead to next quarter: “Net sales are expected to be between $12.9 billion and $14.3 billion, or to grow between 19% and 31% compared with third quarter 2011. Operating income (loss) is expected to be between $(350) million and $(50) million, down from $79 million in the comparable prior year period.”