Despite the football team’s struggles on the field, the Dallas Cowboys are still No. 1 in the sports business world.The Cowboys became the first U.S. sports franchise to top $3 billion in valuation when Forbes magazine released its annual estimates of NFL franchise values.For the eighth straight year, the Cowboys — acquired by Jerry Jones in 1989 for $150 million — are worth the most of all 32 NFL franchises. Valued at $3.2 billion, only the soccer club Real Madrid at $3.4 billion is worth more among global sports teams.Dallas posted the NFL’s highest revenue, $560 million, and operating income, $246 million. That was far ahead of the second-place New England Patriots, worth $2.6 billion with $428 million in revenues and $147 million in operating income. Forbes estimates that the value of the Cowboys surged by 39 percent in the past year as NFL teams took in record revenue from broadcasting and licensing fees. “To be sure, it is a great time to own an NFL team, regardless of market,” the magazine said.The Cowboys benefit from their strong brand name, a high-dollar home with Arlington’s AT&T Stadium and growing Dallas-Fort Worth market.“The Cowboys are a marketing juggernaut,” Forbes wrote, “that is launching two new deals this season that will align the blue star with global luxury watch and cruise line brands, two categories NFL teams have previously ignored or have been unable to tap.” The magazine referred to deals with Hublot and Carnival that “will pay the team in the low seven figures combined annually over five years.”The Patriots had the biggest increase in value, up 44 percent from last year. The average NFL franchise value is $1.43 billion, the highest in the 17 years the business magazine has tracked professional football and up 23 percent, the largest increase in one year since 1999. Forbes determines team values using equity plus net debt figures, and accounts for each team’s current stadium situation, with adjustments for pending new stadiums and renovations to existing ones. Washington ($2.4 billion) is third in value, up 41 percent since the last rankings, and the New York Giants ($2.1 billion) are fourth. For the 2013 season, the average NFL team generated record revenue of $299 million and operating income of $53 million. Each franchise received a record $170 million of national revenue, mainly from league broadcasting and licensing fees. At the bottom of the pack is the Buffalo Bills, worth $935 million and currently for sale after owner Ralph Wilson’s death, and St. Louis Rams at $930 million. But every team grew in worth, the lowest increase being Arizona at 4 percent.