Apple’s iPads took five of the top 15 sales slots at major retailers, including Wal-Mart, Target and Best Buy, according to InfoScout. Reuters

During last week’s Black Friday sales, the loyalty of Android users was sorely tested when about four out of every 10 iPads sold during the one of busiest shopping days in the year, were bought by users of Android-powered smartphones, according to a new report.

InfoScout, a retail analytics firm in San Francisco, said in a blog post that it tracked more than 90,000 shopping trip receipts during Black Friday, and found that roughly 40 percent of iPad purchases were attributed to existing Android smartphone users.

“This discovery clearly poses a challenge for Android moving forward and heightens the importance of Chromecast as Google (NASDAQ:GOOG) competes for mindshare in the living room of the future,” the report said.

Announced in July, Chromecast is a digital media player, which plays audio and video content on a high-definition television by streaming it via Wi-Fi from the Internet or local network.

According to InfoScout, Apple’s (NASDAQ:AAPL) iPads took five of the top 15 sales slots at major retailers, including Wal-Mart (NYSE:WMT), Target (NYSE:TGT) and Best Buy (NYSE:BBY). While the 16GB iPad mini topped the list at Wal-Mart, the 16GB iPad Air, 16GB iPad mini and 32GB iPad Air secured the top three positions at Target.

Apple’s iPads took five of the top 15 sales slots at major retailers. InfoScout

Meanwhile, a report from Apple Insider said that demand for Apple’s popular products was “robust” on Black Friday and the company stepped up to meet soaring demand with a plentiful supply of iPhone 5s and iPad Air units at its stores.

The report said, citing Chris Whitmore of Deutsche Bank, who polled more than 100 stores during the weekend to evaluate demand for Apple products, that the 128GB version of the iPad Air was sold out in a few locations, while the iPhone 5s was in ample supply at Apple's stores.

However, this was not the case with the Retina iPad mini as its supply was constrained during the period. The Wi-Fi-only model of the tablet had a 13 percent stock-out rate at Apple stores and the cellular model was out of stock at 20 percent of Apple stores, Apple Insider reported.