About 2.5 million Chromebooks were sold globally in 2013, or about 1 percent of the entire PC market, according to market research firm IDC. But most of those sales were driven by consumers, not by enterprise users. The Chromebook, introduced in 2011, is still an outlier for most businesses, even as it becomes an alternative for consumers and schools. By 2017, IDC expects the Chromebook to reach about 6 million shipments, or more than 2 percent of the PC market. (There were 314.6 million PCs shipped in 2013.)