Growing without market-share tells us comparatively little.
And to be the person for once that posts the obligatory xkcd comic: http://xkcd.com/1102/
On HN, you could give people the benefit of doubt and assume that market-share growth wouldn't be brought up unless the numbers were large enough. I would refrain from quoting that figure if it went from say 10,000 units to 20,000.
Last quarter, iPhone sales were 31 million devices and WP8 sales were 7.4 million devices. If WP8 is selling one device for every 4 iPhones, that is indeed a decent result relative to where they started off from.
According to the author, MS should abandon the fastest growing class of computing devices. What kind of a strategy is that?!
Meanwhile, Windows Phone sales are up 77% YoY.