The graph shows the amount spent on gaming merchandise according to gamers in the United States.
Gaming Market Exploded in 2016, Led by Mobile and PC
Pro athletes stay in the game with D1 Sports Training, high-end gyms – The Denver Post
U.S. consumer spending on mobile gaming reaches 28% of the global market - Gaming And Media
U.S. iPhone Users Will Spend an Average of $88 Per Year on Apps by 2020, an 86% Increase from 2016
The Best Video Game Subscription Services
8 key facts about South Korea Mobile Game Industry (update Mar 2019) - Chandler Nguyen
The average US iPhone owner spent $40 in App Store purchases during 2016
Pac-Man - Wikipedia
Global: mobile games revenue 2017-2027
What percentage of social gamers purchase virtual goods? How much do they spend on average? - Quora