Not really, you easily can get 2X or more entertainment value from having a good multiplayer.  How many hundred of hours/days could you spend on a single player game compared to MMO/FPSs?  BTW, it is very difficult to create a good multiplayer game that is balanced and deep enough to be competitive at the highest level of play - only a handful of companies are really capable of doing that.  Single player games just have to be entertaining, multiplayer has to be entertaining and fun with the added headache of not being able to make people do what you want them to do.

Is this not true of all consoles? PS3 and Wii games sell better when there is competitive multiplayer involved, too. Its part of a games lasting appeal. Having a strong single player campaign mode is a must, but what keeps you playing a game for months to years later is the multiplayer, if it is good enough.

And why did you just do NA sales and not worldwide? Anything above 500k for just one region is astounding.

A complete game is a complete game. A lot of games feel incomplete because they tacked on a multiplayer and wasted time on it instead of the main mode.

Alan Wake, Halo Reach, Fable 3, Natal + price cut = All will contribute to sales increase.

PS3 has only one big hyped game left this year unless Last Guardian makes it out.

+ Multiplat games sell really well on 360 and they always help.

I think I am missing the point but Splinter Cell at almost 500k in a couple weeks is pretty solid numbers. Final Fantasy is losing sales to PS3 owners. Over 1 million is pretty good number for any game regardless of metascore so Mass Effect is doing alright. So Bayonetta and Just Cause 2 are your best arguments; however, they are also multiplatform games. If you look at the WW numbers for Bayonetta it is over 1 million and Just Cause 2 has done around 800k with no Japan release. Furthermore, the metscore for both FFXIII and Just Cause is higher on PS3 so personally I think your argument should be based more around shooters vs non shooters.

although i agree that having a good multiplayer will give you a lot more bang for your buck, i disagree that single player have to just be "entertaining". I think SP games NEED to be fun and DEEP in order to be the greatest, or else it won't be entertaining at all. =P

So over a million copies sold in one region is underwhelming now? The game will likely make a profit from just the US sales, and the game is multi-platform! The PC sales will be close to pure profit! Further, the developers have claimed that going more shooterish route, which competitive multi-player would push it further down, was not well received by fans. If you want to do it by comparison then I would say any game that isn't a mini-game collection is underwhelming because of the Wii series. Judging a games absolute success based on relative success just does not make sense. Judge the sales on their own merit instead of based on a comparison to series that may or may not have a bigger fanbase anyways.

The 360 has a lot of people paying to be able to play online, and online is a core element of the console, so online games selling better wouldn't surprise me.

However, I wouldn't say that SP games are underwhelming on 360, as many have performed well globally. I'd say that SP/MP titles simply have a better chance of performing really well on 360 (although good WRPGs do sell well on the console, too).

The fact is MP is popular, games with MP sell very well on PS3, too.

I rarely play MP myself (I find it boring and repetitive ironically enough) but I can plainly see what is popular right now (and has been for a while).

Just above 500K in one region outstanding? I beg to differ. There are over 20 million 360s in USA (and that's not counting the rest of America, and VGC numbers certainly include something else more than just USA, somehow)  500K or even 600K is not outstanding by any means especially when it's about critically acclaimed/hyped/well-advertised games. And it's so funny you say above 500K when the whole list I presented doesn't have ANY game above 500K except Mass Effect 2 and FF13. Conviction will certainly pass 500K. Oh no sir, 500K for a 20 million installed base is a flop in any book when talking about high-budget critically acclaimed games.

I can't think of a single game that I have enjoyed that had competitve multiplayer since Duke Nukem 3d.