A flop? I very much doubt it.
I don't think there is any doubt that GT6 had a much lower production cost than GT5. Besides all the reused assets and components, the dramatically shorter development time alone probably equates to millions of dollars less.
I'm pretty sure Sony had lower expectations when they decided to go for a second PS3 Gran Turismo, as well. I think they were willing to trade lower total sales for the chance to extend the life of the PS3 and make some profit off a game where much of the work was already done.
As far as this being an indicator for the health of the series, isn't that a bit silly? It's a title that isn't all that different from its predecessor that has been released after the generation has ended--using the sales of GT6 to draw conclusions about the franchise itself is nonsensical.
Really, when we start talking about "flop" for a game that will ultimately sell millions of units despite all the mitigating factors, it's really just so much fan noise.
One other thing I'd like to point out, for those talking about installed base, that number is NOT the total units sold. Installed base is the number of console in active use. The longer a generation lasts, the more the installed base percentage is effected by dead units. That's why some analysts think the PS3 installed base passed the 360's installed base a long time ago.
