Super Bowl ads reveal a growing preference for 60-second spots that allow time to tell a story.

If there’s ever a time people want to linger over TV commercials, it’s during the Super Bowl – and this year, advertisers will oblige, running longer spots that do more storytelling.

Super Bowl advertisers in recent years have made a practice out of seeding or teasing their commercials via YouTube, Facebook, Twitter, and blogs. Among a few questions, it raises this one: While the online viral may produce buzz for creative agencies behind the TV work, does the seeding tactic actually have a positive impact for the brand spending big money on the uber-premium TV inventory?

According to Ace Metrix, 40 percent of last year’s final version spots were released online before they aired during Super Bowl XLV (45). The Mountain View, CA-based media research firm expects that number to be closer to 60 percent for Super Bowl XLVI.

Peter Daboll, Ace Metrix CEO, said his company surveyed 500 consumers last year about the ads they saw under sports television’s ultimate spotlight. Daboll said there was a scattershot of negative feedback associated with the seeding tactic.

“We have seen some commentary that it can be a bit of a letdown come Super Bowl Sunday if they’ve already seen the ads,” he said. “But it’s still a very small percentage of the viewing audience that actually watches the spots before the game.”

Another question: Are there best practices for seeding TV ads, especially for the Super Bowl? Josh Seifert, a senior marketing strategist at Brooklyn, NY-based digital agency Huge, suggests there is a growing artfulness to the tactic.

“Simply running a spot ahead of time as an online pre-roll probably doesn’t help a brand that much, because it’s not really buzz-worthy,” Seifert explained. “But releasing a spot early as an exclusive for loyal brand advocates within social media could be a valuable way to build buzz and make consumers feel more deeply connected than they might seeing a spot along with everyone else.”

While some brands release the full version of their Super Bowl spot in the days leading up to the event, others produce dedicated online-only variations to build buzz without emptying their creative arsenal. Some advertisers release such teasers while also “leaking” their complete spot.