In the search for more credibility on sales, seeing as Craig says the actual 'hard sales-figures' are undisclosed to the majority, the following may be the closest we'll get to the truth... looks like Pro Tools is doing better than i originally surmised.
According to Digital Music Doctor, which has been tracking Digital Audio Workstation (DAW) popularity since 2004. The latest results are pretty surprising: instead of Pro Tools, Imageline’s
FL Studio now takes the cake, both on a quarterly and yearly average basis as of early 2013.
One thing to keep in mind is that this is not based on actual unit sales, rather popularity across search engines (Google, Yahoo+Bing), social networks (Facebook, Twitter) and YouTube. But still, this is quite telling i would think. I'm still not a fan of pro tools, never will be. Ableton live made no sense to me, the interface was ghastly to say the least. Also, according to some other official figure...
in 2010 Propellerhead Reason outsold every other DAW in the US besides Avid Pro Tools.