I think it is going to sell over 100 million units, less than PS2 because of the collapse of the Japanese console market, and because extreme casuals (candy crush players) no longer need any console. PS4 also doesn't have the extra appeal of playing dvds the PS2 had.

On the other side, there is more middle class in the third world nowadays who could get a console.

My guess s 110-130 million units

I prefer the underestimating predictions to the ridiculousness that was Wii going to sell 300 million back in 2008.

I doubt PS4 will sell 100 million. But if the 360/PS3 install base is relatively static then PS4 taking 40% or more of Xb360's install base could mean PS4 cracking 100 million. But it is interesting that the PS/Xbox install base is trending downwards. PS2+Xb>PS3360. So if that's a real trend then PS4bone170million-->160million? If PS4bone is going to combine to 160 million, which is a 10 million shrink from last gen, then it's not too much of a stretch to see the breakdown being PS4 100 million Xb one 60 million. But I think Xb one is on target to sell less than 50 million (but probably more than 30 million), which would either put combined sales at significantly less than 160 million, or PS4 at significantly more than 100 million.

Its quite true that nobody can predict the future but one can always look at current trends and since this gen is already in motion by the look of it it won't change much down the line.

It's hard to predict anything so early in a generation but I think PS4 will fall way behind the 100M line. A shorter generation and a changing gamer culture will mean that it reaches around 60-70M I think.

The PS4 will be on the market for at least 10 years. Sony have said it many times over the years when each console releases and have proved it many times over the years after each console releases.

I pointed all of this out months ago and got laughed out of the room... I also predict that the PS4 is leading the charge to the game industry crashing. You can't support such high end graphics with such a low population of gamers. 100 million would be a good profit to Sony, but I don't think it will even make it there. 70 million is my prediction. That will be an "Okay" profit, but there's no way in hell that it will stay a three person race after this generation. Microsoft is almost certain to drop out in my eyes.

And what were the casuals playing?

The Wii didn't have a drought for its audience. It had Wii Sports and the likes which is all that the casuals want to play.

What?

The PS4 is outselling the PS2 in the same time-frame (the console that sold over 150 million consoles worldwide and was still supported only a few short years ago). That's without any major exclusives and selling on hype and price alone.

Now imagine what happens when the major exclusives/software turn up in the 2nd, 3rd and 4th years, typically the peak years for a consoles sales. For reference, PS2 sold 18, 22 and 20 million units in its 2nd, 3rd and forth full years on the market. Considering its start, PS4 is on course to meet or beat those numbers.

Based on that information, do you really think it won't reach 100 million in its lifetime?

I was wondering the same thing.