“Amercians have been used to in-play ads for 40, 50 years, so culturally this fits right in,” says Rob di Gisi, lecturer in sport management at the University of Pennsylvania’s Wharton School.
“There is very little pushback here. Any changes which make games more Americanised will be embraced without people noticing.”
Fellow US broadcaster Telemundo, which shows matches in Spanish and is aimed at Latino Americans, is one of the few broadcasters which has decided not to show ads during the breaks.
During Canada’s opening match last week, its commentator said: “We prefer the old school way. We should be able to see what the players do.
“We show fans, people enjoying themselves, not the corporate direction of football.”
BBC Sport has contacted Fox Sports and Telemundo for comment.
In other big markets around the world ads are being used too, including in Mexico, Canada, France, Germany, Italy, Spain, China, Japan, India, Australia, the Middle East and Sub-Saharan Africa.
The broadcasters in those territories will not be able to charge prices as high as Fox Sports, and not all are running them for the maximum duration allowed, but the total amount accrued will be huge.
“When you start scaling that up over all the rest of the countries, it’s probably a billion dollars (£756m) from hydration break ads across the globe,” Di Gisi adds.
Having eyeballs on products during in-game breaks doesn’t necessarily guarantee success, however.
“Will advertisers in the hydration break be met with enough discontent that it negates the value of the advertising?” says T. Bettina Cornwell, head of marketing at the University of Oregon.
“It is the case that when brands violate the expected experience, in this case the flow of the game, fans can react negatively.”