ChinaTown Wars was out for 19 days and sold around 89,000 to 90,000. Liberty City Stories sold nearly twice that 19 day total in one week (VG Chartz has something like 160,000 for Week One in North America). That's abysmal (for Chinatown Wars) when you think about the install base size differences. I realize the game is top down, that probably hurt it, because GTA never really was mainstream until they went Sandbox third person.
Sony (I believe it was either Koller, Tretton, or Reaves, likely Reaves he always runs his mouth) said GTA won't have the same impact on the DS as it would have had they made another PSP game. People ragged on him to no end. It looks like he was right.
And I have to agree with him. Whenever you go into a regular store (ie not EB Games/Gamestop, since they actually carry niche DS games from Atlus, Ignition, NIS America, etc.) and look at DS games, you're confronted with 27 gems like Petz Hamster, Imagine Rockstar, etc. Another 20 being various Nintendo first party releases. And like 10 non casual, non shovelware (hi Chicken Shoot DS!) games. It's daunting to get space and successfully launch a title when the retail space is cluttered like that. The same goes for the Wii. Those platforms are very hostile in those regards. This likely hurt Madworld as well.
And I'm sure piracy hurt it bad too. But with the 35 million DS's in the US piracy shouldn't have hurt the game to these levels. No doubt it will have legs. All GTA games have legs. Just I find it hard to believe it will surpass the totals of even the lowest selling GTA PSP games' total (3 million).