Apple is projected to enjoy huge Mac sales from Black Friday, the biggest shopping day in a year, analyst said on Monday, citing third-party retailers as the key.

Kaufman Brothers analyst Shaw Wu said on Monday that many resellers reported low inventory and ran out of stock for Macs.

Promotions through third-party retailers including Amazon.com, Best Buy, Wal-Mart and Target were more aggressive than usual, Wu said in the note, with discounts as much as 20% vs. previous years of 11%-13%. Some even bundled generous gift cards (as much as $50 for iPods and $150 for Macs) to entice buyers. So far, many third-party discounts (though maybe not as aggressive) are continuing beyond Black Friday.

Apple offered modest discounts between 4 percent and 10 percent through its retail stores and Web site, but third-party retailers were more aggressive than usual to boost sales, Wu said.

The move, according to Wu, had pushed Mac inventory to limited or no availability at usually in-stock locations like Amazon.com and Best Buy.

This includes both models of iMacs (entry-level 21.5-inch and higher-end 27-inch versions) as well as the entry-level MacBook, Wu said.

Wu attributes this to unexpected strong demand driven by Windows 7 and Macs commanding twice to thrice the (average selling price) of PCs.

As there are still five more weeks left to end the quarter, Wu said he believes his above-consensus forecast of 2.9 million Mac sales for the December quarter could be likely conservative.

Moreover, Wu said that foot traffic at Apple's retail stores was strong and sales of Macs, iPhones and iPods appeared brisk. The Black Friday weekend is said to account for about 10 percent of holiday sales.

Kaufman Brothers has maintained its price target of $235 for Apple's stock and reiterated its buy rating.

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