Honestly, with the PSP I think it keeps selling because even though people don't use them very often, they try to justify thier purchase to a friend by showing off what their PSP can do. That friend thinks its cool and decides to get one for themselves one day, and the PSP gets put righ back on the shelf to collect dust once again.
I never see these things anywhere, because no one is using them in public. I have a friend that swears by his PSP and the movies that it plays, but I call him retarded, cause he only uses it at home and he has the movie on DVD already, and he only owns one game and never plays it. His PSP is collecting dust, but he always pushes for someone else to get one, because he has one and its the coolest thing ever and he uses it all the time

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PSP is a status symbol, saying that you could afford one & are a "cool" gamer, but most of the people that I know that bought one never use, never take it anywhere and now regret having bought it for reasons stated before this.
They will all be converted to DS once I get my
BLACK DS Lite, just like I converted them all to GC with my Panasonic Q and SSBM combo.