Well one I have been very consistent on this. Number two, most of these mobile gamers do not actually spend any money at all. Here's a study that concluded only 1.9% of mobile gamers actually ever spend any real money on the mobile games they're playing:

http://www.techtimes.com/articles/144329/20160325/report-finds-1-9-percent-mobile-gamers-make-app-purchases.htm

The majority of the revenue from these games is coming from the free advertising, most people don't use actual money to buy any of the in-app purchases but are willing to put up with shitty ads. Don't confuse revenue with money spent. 

This is where your vaunted Wii Sports/Fit/Brain Training audience has left to and they will never come back. Actually the fact that these people won't even spend $2-$3 on a app anymore shows one key part of the problem I've been saying for ages. You can't give these poeple, who don't particularily care that much about gaming in the first place, thousands of free games that can occupy any free time they have and then think they're just suddenly going to spend $50 on a video game. Apple and Google poisoned the well and changed the way they view/value games. 

This is why Super Mario Run is not having the type of success Nintendo wanted for it. It is a 2D Mario game after all, fairly full featured, and incredibly accessible to anyone, more than even the console Mario games. And it's cheap ... $10 by Mario standards is cheap. So this should naturally be a big hit, right? Wrong. These people do not want to spend even $10 even though millions are willing to download it. They won't spend the money though. Because they have an attitude of "I'm not spending money on games", that's what they've learned from the mobile market. 

Nintendo is doing just fine with Switch without casuals, if they can focus on console experiences that can be played on the go (something that even the 3DS cannot really do), they have a good enough hook for a system that they don't need these people. They'll have to work harder, make sure they market correctly, make sure they are really on top of their release lineup and the quality of the games they are releasing, but that's not neccessarily a bad thing as Nintendo is awful when they get lazy. 

Fate Grand Order just got announced for english localization, so expect those numbers to increase when the game releases over in the U.S

Ive been playing Fate GO since 2015 and its actually pretty great, a nice RPG that ive enjoyed a lot honestly... i can see why this games make so MUCH money, (that being said ive been F2P since launch and i dont plan to change that).

iOS developers earned $26.5 billion in 2017... since Apple gets 30% and the developers 70%, the total AppStore revenue in 2017 should be around 38 billion dollars. And the biggest share of the app revenue is from games.

https://www.apple.com/newsroom/2018/01/app-store-kicks-off-2018-with-record-breaking-holiday-season/

Is fate a Sony game?

The annual revenues for iOS and Android games are still incredible.

Both Apple's AppStore and Google's PlayStore have grown over a third over the previous year; from $43.6 billion to $58.6 billion.



The main share of it are still games, where the growth is estimated at 30%; from $37 billion to $48 billion.



For comparison:

Sony enjoyed a 6.3% increase in revenue from the PlayStation division to $14.7 billion in the last fiscal year, including hardware sales and PlayStation services such as PS+ subscriptions:



Nintendo had a revenue of just $ 4.4 billion in the last fiscal year (including hardware sales, Amiibos, their share of the Pokemon Go earnings...), but is likely to fare significantly better this year thanks to the Switch's success.



SteamSpy estimated annual sales of $ 3.5 billion in 2016 at Valve's platform:

Thanks for the information Conina :).