It sold well enough imo.

Huge mistake from Sony to release this game during the time in 2013 when PS4 launched.
If you ask me the game should have never been called Gran Turismo 6, it should have been a release on PS Vita and it should have been called Gran Turismo Vita. The game and especially PS Vita would have got much more attention during holidays 2013 if this had happened. Maybe this game would have changed the whole PS Vita situation? I mean the franchise is big enough.

1. GT6 should have outsold Fifa considering past success of GT and it was exclusive. Fifa lost sales from cross plat. Ghosts did great between 7th gen and 8th gen, but also lost sales on 7th gen from cross plat.

2. PS3 indeed was selling a lot of software in 2013 and 2014. Sharp decline though.

3. Looked it up, digital only. Therefore its irrelevant. Those deals dont have big impact either way. Advanced Warfare was free on 8th gen if you bought it digitally on 7th gen.

I don't want to argue whether you believe the launch of PS4/XB1 had anything to do with GT6 selling half of what mainline GT games usually sell but I think Farsala's point is that many AAA games releasing in the months before PS4/XB1 had various kinds of upgrade deals. Naturally, GT6 didn't have anything of that kind because it didn't have a next gen version.

I think it's fair to assume that GT6's sales would be higher if it had been a cross gen release. I also think that even GT6's last gen sales (PS3) could've been better if PS3 owners had the possibility to buy and play the game on PS3 at launch and then pay $10 for a next gen upgrade and have all progress transferred when they finally decide to buy a PS4.

Many holiday 2013 AAA games had these $10 PS4/XB1 upgrade deals (both physical and digital) and progress transfers including:

Assassin's Creed IV: Black Flag (Gamestop, Amazon, Amazon UK, Best Buy, PlayStation Store, Microsoft Store)
Battlefield 4 (Gamestop, Amazon, Amazon UK, Best Buy, PlayStation Store, Microsoft Store)
Call of Duty: Ghosts (Gamestop, Amazon, Amazon UK, Best Buy, PlayStation Store, Microsoft Store)
FIFA 14 (Gamestop, Amazon, Amazon UK, Best Buy, Microsoft Store)
Madden NFL 25 (Gamestop, Amazon, Amazon UK, Microsoft Store)
NBA 2K14 (Amazon, Amazon UK, Microsoft Store)
Need for Speed: Rivals (Amazon, Amazon UK, Best Buy, Microsoft Store)
Injustice: Gods Among Us (PlayStation Store)

I agree GT6's total sales would have been better as a crossplat.

But I could also argue it would have sold worse on PS3 had there been a crossplat option. Many would have bought it for PS4 and ignored it on PS3.

I'll just end on this, GT6 was poorly handled and had a massive decline in sales because of it. GT6 is not a success story in my eyes, it was poorly handled and suffered from it. 5 million is very respectable for most games, but this was a mainline release in the series and could have done better.

1: If it was annouced that buyers would have the option to get a PS4 version of GT6 for $10 and all progress would carry over from PS3, I definitely think more PS3 owners would've bought the game to play it at launch and then take advantage of the upgrade deal when they were in possession of a PS4.

2: I agree. Gran Turismo 6 was held back by being last gen only. Many would've bought it for PS4. The game would probably be at 8+ mill at the moment.

Re-read my comment and think a bit. Attach ratio for games on different stages of a consoles lifecycle are not relevant. If they were, Halo 4 would be a flop compared to Halo 3 and Halo 5 would be the most succesfull entry of all time. While a larger install base helps, it doesn't scale linearly with game sales. So comparing 5/15 and 5/85 won't say much about the results. CoD sells less on PS360 since two games ago, even if the install base of the current gen is smaller than just one of the twins.

Of course Halo 5 didn't flopped, the sales decrease is linked to the share MS lost with the X1. GT6 is a trickier question, but it also launched at a terrible time frame, with a PS3 successor already out. It's a similar effect to what happened with Gears and GoW at the end of the gen.

I had given up looking for updated Polyphony Digital sales numbers, but at last they did it! GT6 had a big drop compared for second main GT games on previous consoles, but GT5 eventually became the second best selling GT game ever, and GT5 Prologue is the best selling amongst Prologue and other non-main GT games ever.
Overall, GT games sold the most on PS2, but the user base was the largest, while GT games on PS3 outsold those on PS1 by a good margin despite their console still providing a smaller user base.
GT5 is the single GT game with the highest attach rate, and overall GT games attach rate on PS3 is currently the highest.
So GT6 drop compared to GT5 is the only negative data for PS3 main GT games, and smaller user base, huge sales and attach rate of previous PS3 GT games, both GT5 and GT6 being released quite late and also the unbeatable amount of stuff GT5 gave gamers, both at launch and with successive free and premium downloads, partially justify this drop.

OK, I didn't consider that, so added to all the other factors, the drop has even more justifications. The conclusion can be only one, GT is alive and kickin'.

I guess GTS will be even further down the road as it seems to be severely lacking in singleplayer content which is a shame as I looked forward to a play a Gran Turismo again but as it seems the game will not be a standard GT game by any means and surveys already suggest that many people think the same.