Jim Manley via cctalk <cctalk at classiccmp.org>
writes:
  Many are unaware that the largest fraction of
CP/M licenses ever sold
 were for the Microsoft Softcard for the Apple ][ (about 300,000 sold,
 all told), 
Do you mean sold up to that point? Amstrad went on to sell several
million PCWs with CP/M later in the 1980s. (They say 8 million on
http://www.amstrad.com/products/archive/, but that includes the
much less popular PCW16 which wasn't a CP/M machine.) 
Thw Wikipedia page fot the Softcard has more numbers and dates.