Citigroup analysts doubled down on their Kindle sales estimates, bumping their prediction up to 380,000 units for 2008.

``Kindle is becoming the iPod of the book world,'' analyst Mark Mahaney said in a statement issued earlier this week. ``Kindle could be one of the top `gadget' gifts this holiday season.''

According to Bloomberg, Amazon's stock got a bump of 6.6 percent around the time that the announcement hit the wires.

Rumors were circulating last month that Amazon is looking to issue a new version of the device come October.

The original Kindle debuted in November of last year.