Not trying to be rude but your logic is flawed. Most people who purchase consoles are casuals. There are only a handful of devoted fans for each brand. Most people will flock to whatever system is popular and Mario Kart is one of those games that will attract them to the Wii U. Will it have Wii sales? Obviously not, but to think that it will obtain only a marginal hold of 40K weekly is just not using common sense.  

I know it's just me saying this, but 3 people I know are buying a Wii U just for this game.

Online is gonna kick ASS!

Lol that was funny man I believe the wii u is going to hit its stride the big guns are here and to all the haters wii u will be continuing atleast tell late 2016 early 2017 I know you all want it to fail it may not do the greatest but sorry they.are not discontining any time soon

SM3DW + other games + new bundles + price cut + holidays could barely keep the Wii U in that range and it's already back down to 30k, so I don't know about that.

But playing Mario Kart alone is ass. :(

You really don't have Wiimotes already? Afterall that was the reason why one wasn't included with the Wii U in the first place. Plus if one really needs a Wiimote, they can just buy one! Also, online play is a thing!

Bolded: It already has failed.

Underlined: You have more confidence than Nintendo then.

Italicized: The market will determine that and so far the market has rejected it. You can't expect retailers to keep being used as warehouses holding on to the Wii U and it not selling. Eventully, and it has already started, the Wii U's shelf space will dwindle to a small section. Shelf space is valuable to retailers and they want products that move fast as that's what their profits depend on. When it shrinks at retailers it will shrink in sales as well. People wont see it. The ones that do will see the miniscule amount of games compared to the other systems (because of the limited space).

Having only just read through this, I'll start by referring back to the argument about the Wii, and whether its success was down to the hardware selling software or vice versa - both sides of the argument are wrong, IMO. The Wii and all its sports related games were cleverly marketed together as a package - the hardware and software sold each other. That was what underpinned the Wii's success and grabbed the imagination of the public over the first couple of years after launch.

By the time Mario Kart Wii was released, the install base was already 20 million. The game's lifetime sales went on to 34 million on a console that topped 100 million. Mario Kart, because it's a racer, has a wider appeal than the side-scrolling Super Mario Bros series. New Super Mario Bros Wii only managed 27 million in comparison.

In contrast, the Wii U suffered an identity crisis, and what little marketing there was, came across as confusing. The damage has been done, and rather than save the Wii U, Mario Kart 8 is now all about damage limitation. However, I think that the Wii U will benefit more from MK8 than some might believe, simply because of the huge exposure and appeal Mario Kart Wii had. At this moment in time, Mario Kart 8 is the biggest reason for buying a Wii U, and bundling the game in with the console is a smart move.

Just today on Amazon UK I have seen the MK8 hardware bundle rise 8 places through the pre-order charts to number 43 (at the time of this post) and the old white Wii wheel jumping up 200 places. And that's in a country where there has been little to no interest in the Wii U.

It would be foolish to think that every Wii U owner has a Wii U because they are a Nintendo fan, and that only Nintendo fans will by MK8. I have seen enough posts on these forums to know that people do own more than one console, and that people do buy the Wii U as a second console for the Nintendo exclusives.

I don't like to predict, but I feel confident that even after the inevitable bump after release, Wii U sales will eventually settle at few thousand a week more globally than they are at the moment, especially if Nintendo keep to their promise of continual advertising through to the end of the year. Although the Wii U will never be the phenomenon the Wii was, and may not even live up to any of its other predecessors, the impact of MK8's release could well be enough to positively impact the sales of existing and subsequent games on the system.

In short, I don't think MK8 will 'save' the Wii U on its own, but it sure has the potential to get the ball rolling.

SM3DW did not have the mass appeal that MK8 does. Part of the problem was that it lost a lot of hype when the initial trailer was revealed and unfortunately did not regain it till near launch. Mario galaxy on sold 1/3 of what MKWii managed. It's safe to assume that MK8 will help the Wii U sustain better weekly sales (imo 70k/week does not sound far fetched)

I didn't say just SM3DW alone! Also, SM3DL n MK7 have sold roughly the same amount. MKWii managed to pull away from Galaxy and well everything thanks to motion controls and Wii wheel, but as Wii Sports/Fit/Party on Wii U have shown, motion controls have lost their mass market appeal. So now Mario Kart is back to selling like it normally does, hence the numbers on 3DS.