But nobody is actually willing to put themselves out on a limb and deny that Pokemon has not been responsible for the sale of tens of millions of hand helds.
People will buy something inexpensive like a hand held game player for one game or franchise, even if they end up buying more games down the line simply because they already have the player.
I bought three Nintendo hand helds for one franchise: Advance Wars. While there were plenty of titles I was glad to see in portable format (Link to the Past, Metroid, Final Fight, Puzzle Fighter, etc.) to add to a collection, they were only bought because I already had the hardware.
The only thing keeping me from buying a PSP was the lack of that one game I absolutely felt compelled to play. That and I don't need another hand held device that I'll never carry around like a lunch box. At best, I'll keep a phone on me. The sub compact camera only goes with me when I have an extra pocket, or there's a good chance I'll want decent photos.
4 iPods from various generations rarely accompany me anywhere. The nano is for exercising, the video for watching videos on a short trip without a laptop, but otherwise it's just extra junk to carry around that I won't use.
The only time the DS goes with me is when I know I'll have a lot of downtime as it is a great time killer that takes less space than a paperback book. And only if I'm carrying a back pack.
I would rarely ever use a PSP to watch videos on the go or listen to MP3s on the go. An iPod is smaller. But if I had to choose one for games and media, then the PSP does everything.
After looking at all the things the PSP can do, it really is an all in one portable entertainment device. Minus a video/still camera. In that respect, only the iPhone trumps it, which is currently unproven as a gaming platform.
So even though I need a sixth gaming platform like I need a hole in the head, I just decided to buy one after having no interest in the PSP since it debuted.