PC World’s article
PDA Sales Increase Sharply
summarizes a Gartner Group report on worldwide PDA sales for Q1 2005.
The article comments on Gartner’s conclusion that RIM Blackberry line is the #1 selling PDA worldwide with 21% of the market compared to PalmOne’s 18% share.
The article also mentions that
it did not count sales of smart phones, such as PalmOne’s Treo 650.
My question is why is a Blackberry considered a PDA but not a Treo 650?
Is, for example, the PalmOne Tungsten C’s PDA capabilities different from the Treo 650’s?
I can understand why smartphones like the Nokia Series 60 models or the Motorola MPx220 I reviewed recently in…
On the Go with the Motorola MPx220 Camera Phone
…are not considered PDAs.
But, I don’t understand why the Blackberry is a PDA if the Treo 650 is not.
I see an awful lot of Treo 650 devices used by lots of people around me (I use a Windows Mobile based MPx220 myself, btw).
So, I wouldn’t be too surprised if the Treo 650 accounted for a couple of percentage points of total PDA sales if it were included in this report’s statistics.

What do you think? Is the RIM Blackberry really a PDA like a PalmOne Tungsten C or Dell Axim X50v?
Isn’t a Treo 650 a PDA too?