NPD is a less reliable source covering a much smaller market (not that any of them are reliable).
Chromebook sales are about 1% of all PC sales, says ABI Research
http://www.theguardian.com/technology/2014/oct/22/chromebook...
Different source, different paper, different journalist, same conclusion.
The idea that Chromebooks sell in volume is delusional, at this point, and downvotes won't make it any less delusional.
http://betanews.com/2015/02/24/2015-is-year-of-the-chromeboo...