The holiday season has been good to Microsoft. According to the company, it’s selling more of its Surface products than ever before and even making a dent in Apple’s loyal following.

In a blog post from Brian Hall, the corporate vice president of Microsoft devices, November marked the best month ever for Surface sales. According to Hall, a Surface bundle exclusive to Best Buy sold out in its first day of availability.

The results were similar around the world, where Microsoft saw the best week of Surface sales yet in the United Kingdom and the Surface Pen topped Amazon’s PC accessories best seller list for 12 hours in Germany.

Perhaps more surprising than tech products selling well during a month that saw the most online shopping sales in history is Microsoft’s claim the Surface is taking a bite out of Apple. The computing giant reports turning some dedicated MacBook fans into Surface converts.

According to Hall, the reason for the switch is twofold. First and foremost is what he calls the “disappointment of the new MacBook Pro.” The latest iteration of the MacBook Pro, announced earlier this year, included a new Touch Bar feature that added a new way to interact with the device but was absent any other major overhaul.

Hall argues the new notebook from Apple was a letdown “especially among professionals” and Microsoft’s trade-in program has tempted a fair amount of folks to ditch the MacBook for Microsoft.

Of course, all of this evidence is anecdotal. Microsoft offers next to no data in its detailing of its success. The only time Hall invokes numbers in his blog post is to cite the 10 million people who have watched the launch video for Surface Studio, a touchscreen desktop PC.

IBTimes reached out to Microsoft for additional data but has yet to receive a response.

Even without hard data from Microsoft, there is evidence to suggest Surface has been gaining ground on its competition out of Cupertino for some time. The reported figures from Microsoft’s first fiscal quarter of 2017 showed a 38 percent improvement in Surface revenue.

While the Surface has been rising, Apple has had some struggles moving units. Its fourth quarter figures from 2016 showed iPad sales dropped by 6.2 percent compared to the year prior. The company also suffered a 14.4 percent decline in sales of its Macs.