That's difficult to say, every person will have a different view as what classifies as success.

For one person simply recovering a chunk of users, say 30 million, after the disastrous WiiU would be a success.

For another they may only class it as a success if it outsells the 3ds+WiiU, assuming Switch is going to cover both these bases for nintendo.

40 Million+ is a moderate success in my books.

60 Million+ should be the target.

100 million is unreasonable. It's absolutely impossible to reach those numbers with a $299 handheld console in this day when everyone has a smartphone.

And Nintendo knows this very well. 50 million units is reasonable and would qualify at least as a moderate success.

And just because you release an endless runner on the Apple phone doesn't mean you strive to reach the #1 spot on the video games business. Nintendo isn't that out of touch with reality.

However many units it takes for Nintendo to see a healthy profit which sustains a healthy software output

The price of the hardware is also over emphasized on this board. 

I think in reality equally challenging to Nintendo's approach is people are now used to having free games on the go. Thousands of them. I was just at the mall today and the little kid sitting next to me on the mall bench spent like 45 minutes playing some (probably) free game and he's completely into the game. And I'm thinking this kid paid likely nothing for that game. 

Are people now going to want to go back to paying $40-$60 a game? I think that is actually a more challenging part of the Switch model for Nintendo, the genie of free games has been let out of the bottle and it's never going back in the bottle. 

Switch could be $250 or even $200, and I still think it faces a lot of challenges if the games are priced at even 3DS prices. 

Beyond that, 100 million isn't attainable without a new way to play either IMO. Not unless Nintendo finds a new IP that drives hardware adoption, and I'm talking a huge new IP, like Pokemon, GTA, Minecraft sized IP that drives hardware adoption *for years*. 

100 million in not a reasonable expectation, I'd agree with you. And Nintendo wants to be "market leader" now, big whoop. So does Sony. So does Microsoft. Just because Nintendo "wants" something doesn't mean it happens. I'm sure they wanted the Wii U to be a huge 100 million seller too, and they desperately tried everything to get the 3DS to sell 100 million only to fall waaaaay short. 

Ill just say 40-50M.

There's only one system this generation cycle I see that has a shot at 100 million, and that's a Sony system (yet again). And no, not the Vita, *snicker*.

Smartphones/tablets have just changed the entertainment paradigm too much, even in 4-5 years I think it's going to be a problem for even traditional consoles because you'll have phones/tablets that can generate graphics on par with maybe a PS4, and that will be "good enough" graphics for a lot of people. All you'll need is a bluetooth controller.

In fact the Switch might inadvertently actually cause this process to accelerate because if Switch has a little bit of success, you can bet Samsung and other companies will start releasing tablets/phones with cheaper "Joy Con" like attachment controllers.

Right now they are available but they're not really pushed by the big hardware manufactures and they're big/bulky and way overpriced. Someone starts selling a Joy-Con type controller for Samsung tablets/phones for like $30 which is well designed and developers start supporting it ....

There aren't 74 million unique users to even begin with. 

We all know a good chunk of Wii U owners also own a 3DS because they're Nintendo fans. In fact, I'd say the portion of Wii U owners who don't have a 3DS is pretty freaking small, maybe 5 million.

That means you're really looking at 65 million or so and some of that 3DS number is even inflated because people buy multiple portables more readily than multiple consoles. 

I have no less than 4 3DS models (black launch model, Fire Emblem Awakening LE model, 3DS XL Zelda LE, New 3DS XL).

I think at least 50m, though Nintendo wouldn't mind seeing the NS sell 80m+.

My first instinct is to say 30-40m, but this is from the (erroneous) mindset that the Switch is a home console, when in fact it is covering/replacing both Nintendo's home and portable market offerings.

If we are making apples to apples comparisons in terms of unit sales, Switch should be selling closer to the 60m unit life time sales range, arguably over 70m if we simply mash single generation portable and home console sales into one figure, which is not entirely unreasonable.

Of course, what most probably aren't factoring in with regards to their guestimations (let's face it: virtually no one asserting their opinion in this matter has the slightest inkling of what Nintendo's projections are for Switch over the lifetime of the product) is the projected time on the market, which makes all the difference in the world.

Few will argue that the Wii U is being pulled prematurely from the market, to be replaced by Switch, although this assessment is based upon the overextended product life cycle of the original Wii, due equally to the unexpected success on the market as well as the 2008 financial crisis that resulted in all three major console manufacturers extending the duration of the 7th gen.

I stand by the assertion that Nintendo originally had a 4-5 year product lifecycle intended for the Wii (based upon projected sales/demand prior to release), which coincides with the Wii U product lifecycle.

If the Switch is projected to have a similar 4-5 year product lifecycle, that 70m figure suddenly seems like moving the goal posts back in the interest of declaring the product will be a flop before we even have the first year sales figures in.

So, a better question probably would have been directed specifically at those first year sales figures, rather than product lifecycle sales.