Sales of Google's Chromebook surged this year -- outselling Apple's MacBook, according to a study by research group NPD. From January through November 2013, 1.76 million Chromebooks were sold -- that's up from a total of 400,000 sold last year. Altogether, Chromebooks made up 21% of notebook sales in 2013. Meanwhile, NPD's report showed that Apple's desktop and laptop sales dropped 7%.