Microsoft Exec Claims Firefox's Billion Downloads Is Probably BullS

This is Amy Barzdukas, a general manager in charge of Microsoft's Internet Explorer. And she may be smiling in the photo, but nowadays she's bitching a lot. The reason? Firefox's one billion downloads claim:

As with any marketing statement, I'd encourage people to be somewhat sceptical about large number claims. It's an interesting number and I have not seen the math [but] how many internet connected users are there? 1.1 billion, 1.5 billion, something in that area.

She described the number as "interesting math," even while that 1 billion figure includes every download and update since Firefox launched since 2004. Repeated downloads too. And people having multiple computers.

Knowing that, it doesn't seem that crazy to me. What do you think about Amy's claims? And about Firefox figure? [The Guardian]