A generation of American women who grew up playing sports because of Title IX now makes up the television audience that advertisers covet.
Today's adults were young, impressionable fans when Brandi Chastain ripped off her jersey to celebrate the winning penalty kick at the 1999 Women's World Cup, and even earlier when the buzz of soccer landed in the United States for the 1994 men's tournament.
Now those grown-ups are tuning in to this Women's World Cup — with their kids alongside.
Viewership is up big for this summer's tournament, with a major assist coming simply from geography. With the event in Canada, the most important games air in prime time in the U.S. on Fox's networks during the first North American Women's World Cup since 2003.
But patterns within the viewership numbers reflect deeper trends for interest in soccer in general and the women's sport in particular.
A significant source of audience growth comes from what may seem like a surprising place: female fans. Among men ages 25-54, viewership is up a healthy 21 percent from the 2011 tournament in Germany — but it's risen a whopping 91 percent among women in that demographic.
When soccer was more of a niche sport, it made for an audience that was predominantly male. The more mainstream it moves, the broader the interest. The viewership growth for last summer men's World Cup was also boosted by more women tuning in.
The audience for this Women's World Cup is 38 percent female, still well below half but higher than the one-third or so typically seen for major U.S. sports. The average women's college basketball game during the 2013-14 season had 39 percent female viewership, compared with 31 percent for men's basketball, according to Nielsen.
Mike Mulvihill, Fox Sports' senior vice president for programming and research, suspects wider societal trends are also drawing more women to the tournament. Title IX, the educational gender-equity law that led to the surge of girls sports, passed in 1972. So consider the 18-49 demographic that advertisers value. Even the oldest members of that group would have just been starting school when Title IX arrived.
"Now decades after that, I think you're seeing a great interest among women in watching women compete," Mulvihill said.
The shifts are also generational, though in the opposite direction of most trends. Soccer's burgeoning popularity in the U.S. in recent years has been driven by younger viewers, who grew up playing the sport and readily follow the international game through social media and online video.
But it's their older siblings and parents who are inflating the audience for this Women's World Cup. Among adults ages 25-54, viewership is up 40 percent from 2011. That's compared to a 14 percent increase for the 18-34 group, which may also reflect them watching less TV in general.
"We're such a youth-obsessed business, but in the case of soccer, it's the flip side of the coin," Mulvihill said. "You want to mainstream the sport. It can't just be the younger demo."
Even more promising for soccer's mainstream appeal is the intergenerational appeal of this tournament. Of the adults ages 25-54 tuning into U.S. games during the Women's World Cup, nearly 23 percent of them are watching with a child or teenager. That's close to double the rate for the NFL, which has the next highest total among the major sports and TV programming that Fox tracks.
As nice as it is for young people to discover soccer on their own, the path to widespread appeal for a sport is parents passing on a love of the game to their children.
"Time and time again what we hear from people is that the way they became a fan is through someone in the older generation," Mulvihill said.
One very intriguing number is yet to be determined: How many Americans watch Sunday's final between the United States and Japan.
The U.S. men's group stage match against Portugal in last year's World Cup — which started at 5:30 p.m. EDT on a Sunday — set a record for soccer on American English-language TV with 18.2 million viewers on ESPN.
The 1999 women's final, beginning just before 4 p.m. on a Saturday on ABC, was seen by nearly 18 million when the population was smaller. It still holds the record for a rating for a soccer game, watched in 11.4 percent of American homes with televisions.
Sunday's rematch of the 2011 final kicks off at 7 p.m. on Fox on the night of the week with the largest available audience for TV. The network's research shows that the Fourth of July weekend has not lessened Sunday prime-time television viewership in the past, Mulvihill said.
If anything, he hopes that the patriotic spirit of Independence Day will inspire more Americans to root for the home team. Maybe all the way to more records falling.
Network executives prefer to shy away from publicly predicting the size of audiences. But with all the indicators so far, Mulvihill said, "I think those numbers are in play."