If it did had the same attach rates then it would be selling very poorly on X1 since 1/6 of the install base would make on same rates a quarter million franchise that MS would dish really fast.

I don't think so.  It did not reach 1 million and you know it.  Trying to guess what digital sales are is crazy on a console that hides physical console sales.    Forza 6 FAILED.  But I think that Halo 5's failure is much more pronounced.   I understand that they community serves at the pleasere of Phil Spencer and that is like the whole point to everything but still, the exclusives are selling very badly.   I am upset because I thought that those games are the ones that made Xbox gamers so excited about owning the system.   Imagine to my suprise when Call of Duty completely destroys Halo on Xbox One. And look, the same thing happened on PlayStation 4 so maybe everyone is just a bunch of liars and we all want multiplats. 

LOL have you actually looked at the recent physical numbers it already sold over 900K physical copies plus a ton of people I know bought the Utimate Edition digitally like I did for early access to the game.  Plus the game was one sale digitally just a week ago it sold well over a million copies including digitally more then a while ago already.  Foza 6 didn't fail I didn't cost that much to make since it uses the same engine as Forza 5 its not like Forza 3 which was almost a complete reboot over Forza 2 (car models got enhanced, they added a lot more tracks and cars, new car physics engine, every car got fully modeled interior etc etc).  

Yes it indeed was a Faill, you Know that when after the game Launchs the developers begin to Sell Microtransations, that were Hidden and would only be used if the game did not make a lot of Money.

Forza 6's Launch was the same or even worse than Dragon Quest Heros's launch on the USA, the game only sold more Copies after launch because Had a Bundle with the Xbox One, and sold more on Black Friday, dont think that if they did not continue to Bundle the game, that he Magically will sell a lot more than the Launch.

The Funny thing is that Drive Club, launched on October 2014, sold 2 Millions until July 2015, and the game was considered a "Flop", Forza, did less than 1 Million in retail until now and is a game from the "Ultimate Line Up OF the Goddess", i dont see Forza 6, Selling anything  Crazy after the Holiday Season, and  i thing they will announce a new Forza Game, on E3.

this will Hurt a lot the sales of Forza 6, and Driveclub, until now after more than 1 year  are still receiving new things from the developers, this encourage people to buy the game.

I think it's fair to use 20% digital until we have more data. I don't care about what you bought or your friends. 20% is the middle ground for a game like Halo.

So using VGC data (until 12th Dec) Phy + Dig = 3.26M and set to be 3.5M by years end. That's half of the OP prediction and that's end of story.

Until we see proof that Halo has a better Digital percentage we should stick to 20%.

Nope, they did the same thing with Horizon 2.  Plus its not like GT6 where it costs over $120 in real money to buy the most expensive cars via microtransactions.  The tokens are pretty much only for super lazy people since its super easy to earn credits in a the Forza games on the X1.  The only game where tokens where somewhat benefical was Forza 4 where earning credits is somewhat of a grind but at least you can easily unlock free parts for every manufacturer in the game.

They released the Microtransations after the Launch, days after the Launch, this shows that they would not do this if the game were with more units sold, if they released in the same time this would not be a Problem.

you need to Remember that the PR, for Forza 6, was Huge in a lot of countries, a lot of things on internet and on TV, this cost millions and millions just for the PR, i dont remember of GT6, but  if you can get via Game Coin, dont matter if it is easy or hard to get, the Developers can get a lot of Money, for the people that want  to own the cars very fast.

Yes, the totally unecessary cars costed that much on GT6, I spended nill on them.

And GT6 with 5M is a flop, Driveclub with 2M is a flop and Forza 6 with 1M is a success?

The released the microtransaction way after launch they got re introduced on November the 16, the game first launched on September the 9th (digitally).  The PR wasn't that huge and a lot of it was free since Ford is the offical car sponsor for Forza 6. 

http://www.ign.com/articles/2015/11/17/microtransaction-system-returns-to-forza-motorsport-6

Didnt F5 get wrecked for how hard it was to earn top cars.  And all the micro transactions.  Unlike GT were you could earn all cars in F5 some were locked behind a pay wall.  And F5 cost what, speciel ed plus seasons pass and your experience with less then half the content of GT cost 130$.  Awesome.