What is the appeal of cell phone gaming?

Would someone please help me understand the appeal of regularly playing games on your cell phone? My Motorola V500's screen has a viewable area of 3 cm wide by 3.7 cm tall--the image bellow shows my V500 running Bejeweled. I can't image starring at this tiny space for hours playing a mobile game. Sure, I've played Jamdat's Bejeweled while waiting at the dentists' office, but only for a few minutes. I could never sit for hours trying to align tiny crystals on a cell phone, and I certainly wouldn't pay for the pleasure.

I'm a long-time gamer. I've played arcade, PC, console, and handheld games for the last 20 years. I also love gadgets. But the $2 billion mobile games market baffles me. I can understand gaming on an integrated PDA, cell phone, MP3 player device with a screen the size of Sony's PSP, but not a tiny 3 cm by 3.7 cm screen. Perhaps I'm over generalizing my own opinions. A mobile games business worth $2 billion means a great many do enjoy gaming on current cell phone technology. So I'm asking, what is so appealing about cell phone games? Please explain it to me. Please tell me why I should pay for an activity that is essentially a diversion while waiting for someone to clean my teeth.