There has been significant debate on these forums over recent months on the sales potential of the Xbox One and the PS4 respectively.

Specific to VGChartz, the majority of this debate has tended towards the belief that the PS4 will outsell the Xbox One lifetime.  A recent thread asking what the respective sales of these consoles will look like a year from now got me thinking - what sales differential would be required to actually have any impact on the games we will play over the course of this generation?

There is an enormous disincentive to engage in exclusivity for third party publishers.  The basic idea is that if one console gratuituously outsells the other (ala PS2 versus Xbox) it is more likely third party publishers will either publish exclusively on one console for their own reasons (which I think we can all agree will not happen en masse this generation) or make it easier for a console manufacturer to entice them towards exclusivity with incentives (read: money).  This cycle looks to be unique in that there is remarkable similarity in design and power between the two front-running consoles.  The PS4's power advantage is not pegged to have a significant effect on game quality over the Xbox One, and the Xbox One's Kinect is viewed as unlikely to be particularly revoluntionary on any multiplatform games.

So, bearing in mind that none of us can possibly know the future, the costs of game development on next-generation consoles, and the likelihood that neither console will enormously trounce the other, what sales gap (in either direction) would be necessary over the next 5-8 years to make it significantly easier to entice exclusivity from third parties?

The thing to consider is that they'll start making the game about 2 years before it comes out and that's when they'll make the decision on platform, so the difference after 2 years is what matters

But frankly, they are so similar I just don't think they'll bother unless there is a giant gap

I think it will be something like PS4 20-25m and Xbox 15-20m in 2 years, nothing near the requirement

If it was something like 30m PS4 and 10m Xbox, then maybe some smaller devs won't bother with Xbox, but I doubt it

i dont think will see any exclusivity b/c of global sales differentiation, xbox1 will also probably be pretty close to ps4 in the states. if there will be any loss in 3rd party support it will be a number of other things on top of sales like dev. difficulty and freedom/manufactures policies, but even then 3rd parties would just release a crappy port just to get a few more sales

It wont matter... The architecture is too similar... What they will probably do is make it for the X1 and then port it over to the ps4 with better textures and etc or just port it over with no enhancements because making it for the lower powered console with the same architecture is better because then it can run on both consoles with less work... If your including the wiiU then if the wiiU has a large install base, then then will develop for it, if it doesn't then no cause the architecture is different

Like others have said, the tech this gen is to similar not to make games multi-platform.

All we will see this gen is PS4 games with better sound, lighting, physics, resolution, frame rate, etc. As Sony and third parties start to take advantage of the optimizations that are only possible with the extra hardware in the PS4 the gap will grow graphically. That is all I see happening this gen.

Even Kinect, PS4 Camera, Move, Remote Play, and the touch pad will most likely see no real exclusive features. There is just no real insensitive to use any of them due to the amount of work needed to change the game to fit those features.

The best thing for unique gameplay and exclusive content will be the indie games scene. Non funded 3rd party exclusives, unfortunately look to be a thing of the past.

It gets into the age-old argument - is it better that everyone gets to play as many games as possible, or that innovation is spurred through greater competitive exclusivity.

I would argue the former, as the only instance of extensive exclusivity we have is PS1 and PS2 eras, and that wasnt a result of competitive exlusivity so much as one company's domination of the market.

Depends on total sales. If PS4 sells 140 million and Xb one sells 100 million then that 40 million gap really doesn't mean much because Xb one (and brand Xbox) will still have a huge install base and good long term prospects (assuming we get a 9th generation) that any 3rd party would be foolish to look at exclusivity simply on the basis of sales potential.

However if PS4 only sells 70 million and Xb one only sells 30 million then that 40 million gap is substantial.

Personally I think PS4 is likely to sell between 80 and 100 million and Xb one between 60 and 80 million.

And Wii U between 30 and 50 million.

A) Exclusivity will become less and less "common" as install bases pick up because the platform will become less willing to cover the potential loss of sales on competing system just to have something exclusive

B) Gaps between the consoles will be measured more on demographic of potential gamers than volume alone

For instance, it didnt matter how much Wii U penetration existed at time of PS4 and XBO launch... those two are competing for the same demographic while Nintendo Wii U has failed to attract that particular demographic with any meaningful volume.

The bolded is a good point, and one that my OP failed to consider.

Ultimately, a gap could be rendered almost irrelevant, as long as both consoles sell sufficiently that there is a large and viable audience on both of them.