The PSP's software library appeals to many many people, and does it sell like that? Its marketing.. and word of mouth, thats the truth.. that and its the successor to the gameboy the best selling handheld system before the DS. I have a DS, and it's not the god that you guys make it seem to be..
The library of the DS appeals to more people and it's way bigger. Why marketing? If anthing it's Sony's marketing fault for sucking. And if it's word of mouth it's because people liked it, if the PSP doesn't sell because word of mouth it's because they didn't like it as much as the DS, which is when library comes into account. Being the succesor of the gameboy probably helped in the start, but the DS isn't selling hundred of thousands every week because of that. I can say that had a PSP, and it's not the god of multimedia devices that you make it seem to be.