The Kindle is on pace for a very good 2010, according to sources.

Amazon likes to keep its Kindle sales figures pretty close to the vest, so it's been a mystery just how many e-readers the company has sold. But according to a report by Bloomberg, which cites "two people who are aware of the company's sales projections," the company is likely to sell more than 8 million Kindles this year. That's at least 60 percent more than the 5 million units analysts had predicted Amazon would sell in 2010.

Those anonymous sources indicate that the projections show Amazon is "adding share in the e-reader market," where it's going up against Barnes & Noble and Sony, "faster than predicted" by analysts at Citigroup and at least five other securities or research firms.

Of course, how Apple's iPad figures in all this is hard to say, as both Amazon and Barnes & Noble have apps that allow iPad owners to use the device with those companies' respective e-book stores (Apple has its own iBooks app but it offers fewer books for sale than both the Kindle and Nook apps).

The same article mentions that Apple sold 7.46 million iPads from April through September, and many analysts are predicting the iPad will easily surpass the 10 million mark after this holiday buying season.