http://nintendoeverything.com/latest-nintendo-release-schedule-million-sellers-list/?pid=71339&pageid=177474

Nintendo recently stated that they had sold 3.49m units of MK8 as of the end of September. (That's including digital and copies sold to retailers)

All this before its first Christmas season, and with DLC on the way to spur interest.

Mario Kart Double Dash topped out at 6.95m.

Do you think MK8 can top that by the time it stops selling? (Including digital sales)

It's more than halfway there already.

So, not sold then ?

Anyways, it might. We'll have to see what happens this Holiday though. It will sell like crazy along with SSB4.

Sold, just both to consumers and retailers. It's likely closer and therefore more useful than VGChartz's numbers, which not only don't account for digital, but are almost certainly undertracked in terms of boxed copies.

Yes it will.

I think it will over its Lifetime cause the people that buys a wiiU these days are for Nintendo games so the attach rate of MK should be very high

I think Mario Kart is bigger now than it was then (it's always been big, though) so I totally expect MK8 to beat MKDD. It is easily the better game, imo.

Well, the thing is it's not a matter of popularity, or of game quality. It's the WiiU sales that are a problem.

The console still has a pretty bad reputation among the gaming community, even though it's a great console with great games and more great games to come, and that affects the sales a LOT. Seriously, Mario Kart 8 has like a 2:1 attach ratio on the WiiU. Imagine if the console sold at least like the Xbox One. Then it would be a given that MK8 would outsold Double Dash. But unfortunately, if the sales for the WiiU don't get better in the long term, it won't.

Those are shipped numbers ...

With that being said MK8 would need to at least attain 50% attach rate at the end of it's life for it to possibly happen. It's not impossible but I think that's highly improbable considering only 1 WII U title was able to currently achieve it and it'll likely lose that status in the future ...

That's assuming lifetime Wii U sales of 14m. It'll do better than that I reckon.

That's debatable ... 

With this year being very likely the peak for the WII U, I'm surprised that the WII U will go on to sell similar numbers like last year. With the WII U currently tallying up to 2 million units with latest shipment data suggesting an overtrack of 300K units, the WII U has so far sold 1.7 million units this year. If we can take a look at an otpimistic case that the WII U will sale about 50% of it's units for the holdiays that will come to around a total of 3.5 million units which is roughly a 10% increase from last year's sales of 3.2 million units. 

At the end of the year the WII U should come to have sold 8.8 million units and the next year is the WII U's only decent year left since Nintendo will have played every cards they can get their hands on. With another optimistic expectation the WII U should reach 11 million units by then but how exactly is Nintendo supposed to sell 3 million more units when the wells are dried up ?