Amazon announced on Thursday that the 2011 holiday season was the best ever for sales of its Kindle devices. While the online retailer didn’t specifically say just how many devices were sold by model, it did say Amazon customers purchased “millions of Kindle Fires and millions of Kindle eReaders” and more than 1 million devices per week during the month of December. The company also noted that its #1 and #4 best-selling eBooks released this year were published by independent authors through its Kindle Direct Publishing platform. “We are grateful to our customers worldwide for making this the best holiday ever for Kindle,” Amazon.com CEO Jeff Bezos said. “And in a huge milestone for independent publishing, we’d also like to congratulate