The 2008-09 season on Broadway has been a good one for straight plays, thanks to a lineup that proved unusually crowded with a diverse array of offerings.

But that packed sked, with its clear upside for play fans, also resulted in a challenging producing landscape that made recouping an investment, much less making a profit, even more difficult. In a celeb-heavy spring lineup in which theatergoers can choose between shows starring Jane Fonda, Geoffrey Rush and James Gandolfini among other big-name celebs treading the boards, productions need every advantage they can get to stand out.

And in this environment, Tony noms can appear even more valuable than usual.

“We need Tony nominations, we need awards, and more and more behind us to counteract the fact we don’t have a movie star,” says producer Sonia Friedman of her Rialto transfer of “The Norman Conquests,” Alan Ayckbourn’s three-play ensemble comedy that racked up seven nods.

Like “Norman,” Neil LaBute’s “Reasons to Be Pretty” has struggled to attract auds despite a favorable critical reception. The show hopes to gain momentum thanks to a new play nom and thesping recognition for lead actor Thomas Sadoski and featured actress Marin Ireland. “If we hadn’t been the recipient of significant Tony nominations, we would be in more serious trouble,” says producer Jeffrey Richards.

The economic downturn, which in the fall sparked prognostications of a rash of dark theaters on Broadway, has, in fact, helped contribute to the spring’s surprisingly robust lineup. Recessionary fears contributed to the unusually high number of Broadway productions that shuttered in January, a development that freed up major chunks of Broadway real estate for incoming offerings. And in a risky economic climate, limited runs of star-driven plays are among the safest bets on Broadway.

Just ask the producers of “The Seagull,” toplining Kristin Scott Thomas, or of “All My Sons,” starring John Lithgow, Dianne Wiest, Patrick Wilson and paparazzi-fave Katie Holmes. Those two fall productions were among the few this season that recouped their capitalization costs, while early this year, Will Ferrell’s movie-star appeal helped turn his Broadway debut vehicle, “You’re Welcome America: A Final Night With George W Bush,” into a cash cow.

But as the spring sked turned into a straight-play logjam that yielded a spate of positive reviews, several plays found themselves struggling to maintain their hold on the attention of ticketbuyers.

“It’s been a challenge to keep the show in people’s minds,” says Stuart Thompson, producer of “Exit the King,” starring Rush and Susan Sarandon, which is nominated for four Tonys, including one for Rush. “After we opened, even though we had good numbers, we stayed on TV for a while. In another season we may not have done that.

And we’ve done a lot of email blasts just to keep ourselves fresh.”

“Exit” was one of an array of plays that scored head-turning positive reviews, including “Reasons,” “Mary Stuart” and “Norman.”

As happened last season with “August: Osage County,” one play in the crowd drew the majority of the limelight and built up major box office muscle.

Yasmina Reza’s “God of Carnage,” another show of which Thompson is a producer, initially grabbed biz with a starry cast that includes Gandolfini, Marcia Gay Harden, Jeff Daniels and Hope Davis, and then snowballed into a red-hot ticket in the wake of strong reviews. However, with the papers handing out an unusually high number of good notices to straight-play productions, the traditional box office benefits of glowing press were somewhat diluted.

“It’s much harder, compared to the kind of wraps ‘Seagull’ was doing, or ‘Boeing-Boeing’ was doing,” says Friedman, the “Norman” producer who also backed “Seagull” and last season’s revival hit “Boeing-Boeing.” “But those shows weren’t in an environment of 16 plays.”

So with the help of the Tony attention, producers are hoping to pump sales any way they can.

“There’s definitely a lot of discounting that everybody’s doing,” says Arielle Tepper Madover, producer of “Mary Stuart,” nommed for seven Tonys. “It used to be, ‘Oh, we don’t talk about our discounts.’ Now all anyone does is talk about discounts.”

Much has been made of the proliferation of low-price ticket hawkers in Times Square, most wearing sandwich boards for the plays that have sent them out tubthumping.

“Reasons” has often been one of those plays. Richards and his producer partners on the show had previously teamed on last season’s breakout hit “August: Osage County,” and they saw parallels between “August” and “Reasons”: Both came from respected American scribes that had not yet appeared on Broadway; both originated in resident nonprofit theaters; and both featured ensemble casts that, while talented, did not include thesps with much name recognition.

In another season — last season, for instance — strong reviews would have trumped an unknown cast to give the show a boost in profile and B.O.

But in this crowded season, the rules are different.

“We opened amidst a sea of excitement over many TV and film stars coming to Broadway,” Richards says. “Despite excellent reviews, it has been difficult to catch up to the extent we hoped. We’ll have to wait to see what happens.”