There is simply more of something for everyone in F4, if it is as advertised.
How many of the people who bought Skyrim will buy F4, simply because it is a Bethesda game?
I know that's why I bought Skyrim.

Let's just say, hypothetically that everyone who bought Skryim buys F4. That's a tie.
Now pour on the FPS gamers who aren't into fantasy games, the minecraft types that want to build settlements, and then those who will be interested in using mods- aside from Halo Forge (which I don't think will be comparable) this is unprecedented.

It isn't just that it is a well known, money making series. It has much more to offer.

Before this thread I thought it was obvious that Fallout 4 would outsell Skyrim. Even though some people have made good points, I still feel it's going to do that.

I'm not sure, i don't think there will be as many console version's sold due to the lower install base, at least initially anyway, Skyrim sold 9.5 million on PC according to Steamspy, so it will be interesting to see if Fallout is as popular as the Elder Scrolls in that regard.

Over the next few years the console install base will continue to grow. Console players won't have a choice if they want to keep playing new games. We're now at the point where cross-generation releases will start to become uncommon, as games like Fallout 4 just won't work within the limitations of the old-gen hardware. Fallout 4 may take a few years to hit 20 million sales, but then, so did Skyrim. It'll get there, and beyond.

Yeah, it will be interesting to compare the 2 series in popularity, but having to buy a new console doesn't mean they will all buy Fallout 4, also wouldn't used game sales on console only count as one sale instead of more, so i'm not sure how accurate that will be, like i said, i will check Steamspy out of curiosity to see the PC install base.

how will fallout not outsell skyrim? When everyone and there mothers are obsessed with post apocalyptic situations you have shows about building dooms day shelters and the world going wrong with virus outbreaks. Fallout has guns it has zombies....well ghouls it has a good deal of things in popular culture today with a 50's twist I know fallout 4 will outsell skyrim. When you look at it it will appeal to a lot more people then swords and dragons can.

Don't know, I'm just waiting to play it. I'm more interested in playing the game than in numbers.