“There’s no doubt that the incidence of these commercials is at least double what it was five years ago,” said Larry Chiagouris, a professor of marketing at the Pace University Lubin School of Business.

“For the longest time, ads presented the typical American household as Caucasian, heterosexual, two children and two cars in the driveway,” he added. “There’s still a part of the world that’s like that, but there’s a large portion that is nothing like the ‘Father Knows Best’ Americana image. It’s taken the advertising community, and particularly their clients, a long time to come to grips with that. They’re risk averse.”

That relatively new awareness, Mr. Chiagouris said, has resulted in not only more ads with interracial couples, but also more gay and lesbian couples.

The prevalence of these commercials “is a reflection of modern society,” said Sarah Block, the executive vice president and creative director of Leo Burnett USA, who has worked on several ads depicting multiracial families, including commercials for Kraft. “It’s portraying the situation that is out in the world.”

The commercials are a way for a companies to signal that they’re open minded and progressive. “I think there’s an ever increasing demand from customers to understand not just what products and services you provide but also to understand who you are as a company, what your values are,” said Fiona Carter, the chief brand officer of AT&T, which owns DirecTV.