Know: 50,000 games sold on day one is not a smash hit. 500,000 games sold is. Capcom's Monster Hunter Portable 2nd for the PSP did monster business on launch day, moving half a million copies according to early reports (which may overshoot or low-ball the sales figures). Quick inventory of recent portable games with first day sales of 300,000 plus:
Dragon Quest Monsters Joker: 400,000 units
Pokémon Diamond: 500,000 units
Pokémon Pearl: 400,000 units
Final Fantasy 3: 300,000 units
And all of those are DS games. And MH2nd isn't! Meaning that probably every single PSP owner in Japan has purchased this game (or eventually will). PSP dead in Japan? Not so thanks to Monster Hunter Portable 2nd. From what I've heard, this game is Capcom's biggest hit since Resident Evil 2! And if that's true, wow, just wow.