Here's the quote from Adobe's site...
Adobe ® Flash ® Player is the world's most pervasive software platform, used by over 2 million professionals and reaching 99.0% of Internet-enabled desktops in mature markets as well as a wide range of devices
It's interesting that Adobe defines Flash as a "software platform". A javascript-enabled browser could also be defined as such- which would make Adobe's claims of "most pervasive" false, since there are many sites which use javascript but not flash.
Mature Markets include US, Canada, UK, France, Germany, Japan.
Hm, seems like they left out a few ...
Of course, they just want to make people to feel comfortable paying top dollar for their products. (And as someone faced with buying a copy of Flash or Adobe CS4 soon, Holy Cow it's expensive!)