A year ago, NBC marketing chief Adam Stotsky was handed a formidable task: selling viewers on “The Jay Leno Show.”

This year, the mandate is no less daunting — but at least Stotsky doesn’t have to try to reinvent primetime again.

Instead, as NBC continues to recover from the “Leno” debacle, Stotsky and his team have been tasked with bringing growth back to the Peacock.

A lot is riding on NBC’s launch this season. The longtime laggard ended the 2009-10 TV season last among the major nets in viewers and adults 18-49 (though it virtually tied third-place ABC thanks to “Sunday Night Football” and the Olympics), and could claim only two of primetime’s top 25 entertainment series.

“Last year was a challenge, that’s for sure,” Stotsky says. “We were doing something quite innovative and disruptive at 10 p.m. This past year, we spent a lot of time stabilizing the schedule. Now we’re in a position to build patiently.”

But in an age of network erosion, luring back viewers who have fled to cable or other entertainment options isn’t going to be easy.

And Stotsky is faced with launching a hefty seven series this fall — including six over a span of eight nights this month. That’s a risky move for a network in a weak position.

“We’ve definitely got a lot of new product,” he says. “That represents a different kind of challenge, a different kind of pressure.”

But NBC U TV topper Jeff Gaspin told Variety in May that the network’s marketing team would receive more financial support this year — as much as a 40% boost over last year — to help nurse NBC back to health.

And though Stotsky says he’d always like more money, the exec believes his team has “every resource necessary to do what needs to be done this season.”

“The whole company recognizes the challenge of rebuilding the NBC broadcast brand and business,” Stotsky says. “People are stepping up and contributing. We have the financial resources that we need to launch this fall slate.”

Armed with that infusion of marketing dollars, Stotsky and his team have come up with a mantra to rebuild the Peacock’s lineup: “early and often.”

Looking to tap into social media, NBC set the timing of the launch of its fall campaign all the way back in May, following its upfront presentation.

Stotsky says he was inspired by the success last season of Fox’s “Glee” and ABC’s “Modern Family,” both of which generated hefty buzz after their respective networks began hyping the shows in May.

“We had a hypothesis internally that there’s a group of TV enthusiasts out there that recognize that the May upfront is the launch of the fall season in a certain way,” Stotsky says. “We challenged the team to come up with ways to take advantage of this moment in time.”

Counting on those TV fans to spread the word via blogs, Twitter and Facebook, NBC kicked off its campaign via an ad campaign with Time’s Entertainment Weekly, where the network bought ads all summer long.

The Peacock also struck a deal with Microsoft to market NBC shows on 19 different platforms — including MSN, where NBC convinced the site to launch its fall TV preview in May — and the Xbox.

And on NBC.com, the net launched a network affinity program, “Fan It,” in which users build up points in exchange for Peacock tsotchkes. (The program was inspired by 2009’s successful grassroots campaign to save “Chuck.”)

“All of this helped prepare us and propel us to the position we’re in,” Stotsky says. “We’ve seen incredibly strong social-media conversation about our product.

“Our digital media and social-media agencies have been tracking it through the summer, and we’ve seen that translate into broader awareness and intent-to-view.”

That online buzz has now fed into NBC’s more traditional fall push. One of the shows getting some of the heavier marketing support includes Monday entry “The Event,” which will get a big push from “Sunday Night Football.”

Peacock also is bullish on the J.J. Abrams actioner “Undercovers,” which opens Wednesdays at 8 p.m.

Stotsky said NBC is also treating sophomore skein “Parenthood,” which bowed last March, as a new series that should receive more promotional help. NBC moved the season premiere of “Parenthood” up a week, behind the penultimate “America’s Got Talent” episode, to set it apart from the pack of new shows.

And the network is also prepping several viral stunts, such as creating a virtual call center for “Outsourced,” NBC’s Thursday comedy set in a Mumbai call center.

Los Angeles Times staffers might also want to brace for another NBC ad that blurs the line between editorial and advertising: The Peacock has partnered with the paper for a stunt surrounding “Law and Order: Los Angeles,” in a similar vein to the past controversial NBC/”Southland” and Universal Studios/”King Kong” ads in the paper.

Those ads caused a stir at the paper, where staffers said such ads undermined their credibility. But given the noise they generated, NBC U deemed the buys a success.

“Where our ‘Southland’ and King Kong ads left off, ‘LOLA’ will pick up,” Stotsky says, “and hopefully surpass both of these events.”

Stotsky will also rely on NBC U siblings to get the message out. “The Today Show” and iVillage will support “Parenthood,” while the Jimmy Smits starrer “Outlaw” will be hyped on Telemundo. “The Event” will get help from USA Network and Syfy, while Bravo and Oxygen are supporting “Undercovers.”

“Over the course of six years since NBC and Universal came together, the company has done a great job of harnessing the combined sum of its part,” Stotsky says.

Nonetheless, NBC has its work cut out in this crowded fall TV environment. More than 25 new series are set to bow in the first few weeks of the TV season. There are also major timeslot changes being promoted at the nets — and cable’s not taking the fall off either, with big new entries like HBO’s “Boardwalk Empire” threatening to steal broadcast’s thunder.

“Our work is never done,” Stotsky says. “We can’t rest until we put the numbers on the board.”