To combat criticism that the league has not come as far as it should have, executives often repeat a mantra: The W.N.B.A. is ahead of the N.B.A. at a similar period in its development.

Last year’s average W.N.B.A. attendance of 7,318 a game exceeded the 6,749 at the same period of the N.B.A.’s development in the mid-1960s. The N.B.A. then was not the marketing juggernaut it would later become under the former commissioner David Stern and lacked a nurturing, financially well-heeled league as its parent, as the W.N.B.A. has had.

The comparison between the leagues is less favorable now: The N.B.A. is a global sports force, with $5.18 billion in revenue last year, that just set a regular-season attendance record of 17,864 a game.

Still, Val Ackerman, the first W.N.B.A. president, said: “Longevity is itself a victory. There were naysayers around every corner who said we wouldn’t last a year or even two years, and now it’s 20.”

Backed by the “We Got Next” marketing campaign and the ownership of its teams by N.B.A. franchises, the W.N.B.A. started with unexpected strength the year after the United States women’s team won the gold medal at the 1996 Summer Olympics. Original average attendance projections of upward of 4,500 fans in the first season were obliterated in the surprising rush to see the women play. That average attendance of 9,664 in 1997 swelled to a peak of 10,864 in 1998, then began its gradual downward descent.

“The first year or two, sure, there was a lot of sampling and a lot of excitement coming out of the Olympics,” said Rick Welts, president of the N.B.A.’s Golden State Warriors. “The league did a great job launching, but a whole lot of N.B.A. fans looked, watched and said, ‘I don’t like this league that much.’ That was the biggest wake-up call of all, that there was not an automatic migration of N.B.A. fans to the W.N.B.A. It took us a while to figure out that this was not the N.B.A. and we had to approach it differently.”

Silver said his goal within three to five years was to bring attendance back to 10,000, a level the Phoenix Mercury, the Minnesota Lynx and the Liberty approached last year.