Good is a relative term. Now in general, FF13 did do well. 5.55 mil copies is good for any game. However, when comparing it to SE's predicted sales, it doesn't seem so big. FF13 was expected by SE to sell 10 mil just like FF7. [Edit: Actually it was Wada hoping it would sell 10 mil. But, officially they stated 6 mil, which it looks like they will just make. I guess SE didn't have as high as hopes as Wada] And it was released under the same situation as FF7, as well. The first installment of the series on this gen of consoles. It was the first using a new storage format, so the possibilities seemed almost endless. And it had a HUGE amount of hype surrounding its release. But, when all is said and done, it will most likely fall 4 mil short of that 10 mil goal.
If we compare it to the other games in the series, things don't look that great, either. FF8 was able to sell 8.15 mil, and also started a downward trend for sales in the series. FF9 was only able to sell 5.3 mil copies. However, if we look at the circumstances of its release it's not hard to see why. It came out in July of '00, which was 3 months after the lauch of the PS2 and over a 1 1/2 years after the Dreamcast, so this was a time when people were moving on to the next gen. FF10 was able to raise the bar again with 6.6 mil (though VGC has it at 7.95 mil). I'm going to skip the online FF11, since it's pretty obvious why that didn't sell as well. Finally, FF12 sold 5.2 mil (VGC states 5.69 mil). Now, some people say it sold less because of its gameplay deviating from the FF norm. I haven't played this one, so I wouldn't know. However, I do know it launched in March of '06 (Japan) and Nov. of '06 (NA), so the same year as the PS3 launch and a year after the launch of the 360. So, just like FF9, it was a time people were moving onto the next gen of systems. Like I said above, with the circumstances surrounding FF13 it should have sold much better.
Now as far as a flop, I am 100% sure SE made profit off of the game. How much? Not sure, as I don't think they released the budget, but I know it wasn't as much as other installments. I mean FF13 started on the PS2, which they originally developed the White Engine for. When development was switched over to the PS3, they stated they lost 2 years of work since they had to learn how to work on the PS3, as well as retool their engine to work on it. Then when they decided to go multi-plat, they had to refine their engine once again to be multi-platform, later redubbed Crystal Tools. And let's not forget they had to learn how to compensate for the limited storage space of DVD.
I think in the end FF13 will sell somewhere between FF12 and 10. I would qualify that as good, just not great. Especially considering FF7 and FF10 sold so well on install bases that were nowhere near the combined install base of ~70 mil that FF13 released on.
