NBC is betting that an app will stir interest in some of its oldest content. Last Thursday, the network unveiled the "SNL" app, a free app stocked with popular "Saturday Night Live" skits like “More Cowbell” and “Samurai Delicatessen" that NBC is hoping will deepen engagement with one of its longest-running shows. “We think there's a younger demographic that's kind of rediscovering 'SNL,' ” said Rob Hayes, NBC executive vice president of digital entertainment.

While “SNL 40,” which aired in prime time Sunday, was a massive hit for a network special, with more than 23 million people tuning in and more than 1.3 million people chiming in on Twitter, the ratings of "SNL" have been in persistent decline for decades. For the past 10 years, fewer than five percent of American households have tuned to the late-night broadcasts.

That slide may be why NBC has been running a full court press to drive app downloads since its release Thursday. A handful of tech press got a look at the app before it launched, and NBC also aired ads for it during the “SNL 40” broadcast, a practice it will continue for the rest of the "SNL" season. NBC also attached post-roll ads to “SNL 40” clips posted on YouTube following the Sunday broadcast. Those ads drive users directly to the iTunes App Store, where the app has enjoyed a fair amount of visibility since the launch. Hayes said NBC worked with Apple to optimize the app’s design to ensure it would be named an editor’s pick. "They're giving us a ton of promotion," he said.

Hayes declined to mention how many times the app has been downloaded so far.

According to Hayes, close to half of NBC’s digital video content is streamed on mobile devices. The network saw that as a signal that an app filled with short clips, many of them close to the ideal length of three minutes, could succeed, not just as a revenue generator but as a way for younger people to start diving more deeply into the 40-year history of "Saturday Night Live."

At times, it has been hard for younger viewers to investigate that history. NBC spent years fighting aggressively to keep unofficial "SNL" clips off YouTube, and in recent years, the official "SNL" archive has moved from one content portal to another. For a time, the archives lived on Hulu, which is partly owned by NBC parent Comcast. In 2013, Yahoo paid a rumored $10 million for exclusive rights to the library of past clips. That window of exclusivity has since closed, and today those clips are available in a number of locations, including Hulu, NBC's website and Yahoo, as well as the app.

What sets the app apart, Hayes said, is its ability to give users more personalized recommendations based on personal information. First-time users are asked questions at the beginning, including what is their favorite era of the show.

"People don't necessarily identify with seasons so much as decades and eras," Hayes said. Knowing which eras a user likes most allows the algorithm to surface content from different decades that will most appeal to particular users. The recommendations draw on primary research and focus-grouping that NBC has been doing for decades. "Everybody has that golden era that they remember," he said.