Mars spends most of its advertising dollars for its petcare brands — including Pedigree, Cesar and Whiskas — on television, according to the food group's marketing chief.
Andrew Clarke, Mars' chief marketing and customer officer, told CNBC's "Marketing Media Money" program that digital advertising needs to prove that it is effective, just as TV advertising has done.
Mars spends around 60 percent of its marketing budget on TV in its petcare business, while the remaining 40 percent goes on digital ads.
"We really need to prove how our new digital platforms, our media partnerships (work)," Clarke said. "We need to prove that, so it actually does drive sales in the way that we know that sales are driven in a traditional media space."
"I certainly believe a combination of the two (traditional and digital media) is always going to be relevant certainly in the CPG (consumer packaged goods) space," he added.
Large businesses are grappling with where to spend their ad dollars, with many switching marketing money to digital formats. In 2017, Adidas announced it had stepped away from TV advertising as its consumers went online, while website company Wix has no plans to spend money on TV this year, in spite of advertising during the last three Super Bowl broadcasts.
Half of all global ad dollars will be spent online by 2020, according to an estimate by media agency Magna, matching all combined "offline" ad spend, including TV.
Mars spends around 30 percent of its ad budgets on digital means for its candy and food business, which includes brands like Skittles, M&Ms and Dolmio. Digital spend is higher in petcare because it's easier to identify people who own an animal.
"We can get much more targeted now with data and really understanding consumers in new and different ways. What breed of dog or cat might they have (or) their feeding patterns (for example), and therefore make sure the messages that we give them through a marketing perspective are relevant," Clarke said.
Mars still wants to reach a mass audience for its candy business. "But we'll continue to test and learn. We'll continue to experiment. We'll continue to use digital across all of our channels and then we'll put our dollars in the places that give us the best possible return," he said.
Mars mixes a scientific approach to marketing with a focus on creativity. It works with the Ehrenberg-Bass Institute for Marketing Science to understand the return on investment of its ad dollars and won 44 times at the Cannes Lions ad awards in 2017. The many ways to promote its brands to people mean it has never been a more challenging and disruptive time to be a marketer, Clarke told CNBC.