If business-to-business marketing once relied nearly entirely on highly technical selling points, those days are done, victims of online product specs and the storytelling power of video. BBDO, an agency that works with both consumer and business brands, has done more to embrace that shift than any of its rivals.

In a GE commercial called "Childlike Imagination," which broke during the 2014 Winter Olympics and was later nominated for an Emmy Award, BBDO brought out the wonder and magic of industrial equipment like jet engines and wind turbines, telling the client's story through the eyes of a little girl whose mom works for the company.

Indeed, BBDO's work for GE made it the big winner among agencies in the Ad Age B-to-B Best Awards.

And in BBDO's "Solutions That Matter" campaign for FedEx, a TV spot showed a courier sticking with a small-business customer as his company grows from a tiny cubicle to a global enterprise. Transformation is the theme, as desks emerge from the floor, video screens sprout from the walls and the cubicle becomes a skyscraper.

In b-to-b today, like other marketing if not more so, it boils down to reaching people with powerful narratives.

"We've seen a shift to more showing than telling," said John Osborn, president-CEO of BBDO New York, our 2014 B-to-B Agency of the Year. "If you look back over the past decade, some b-to-b stuff can be fairly dense. Now, consistent with the increased importance of video, there is more 'show me' instead of giving people technobabble."

B-to-b makes up about 40% of BBDO's overall business, with a roster that also includes AT&T, Exxon, HP and Monster.com. The agency picked up b-to-b work last year from new clients including SAP, Wells Fargo and CVS Caremark.

"BBDO takes complex, hard-to-understand, complicated ideas and brings them to life," said Andy Goldberg, global creative director at GE, which has been a BBDO client for 94 years. "They are extremely collaborative. They really want to understand the GE business, as well as solve a creative issue."

The agency has led as b-to-b marketing grows to encompass much more than traditional advertising.

"It's not just a TV ad," Mr. Osborn said. "It's everything from tools and tactics to trade shows." That has included developing sales tools, investor programs and educational outreach, such as a program BBDO developed for Monster.com called "Project U," connecting employers and millennials.

But the tool kit also now permanently includes the element most consumers associate with brand-building for fancy cars, breakfast cereal and consumer tech. "Whether it's b-to-c or b-to-b, you're still talking about stories," Mr. Osborn said.