Keith Weed hasn’t shied away from being vocal about the need for marketers to pay closer attention to digital ad buying before.

Monday was no different, when the Unilever marketing chief once again took the stage at Advertising Week New York.

Weed reiterated the need to fix digital advertising, demanding more accountability from digital platforms and stressing on the need for cross-platform measurement.

“This is critical, because at the end of the day, we’ve got to see over the walled gardens of the Googles and the Facebooks and the Twitters and the Snapchats, and be able to measure across the whole market,” he told an engaged Advertising Week audience. “The need as advertisers and marketers is to really understand the dynamics between TV, digital, etc.”

It’s become a common complaint in the world of advertising that dominant tech players like Google and Facebook don’t allow marketers to use their powerful data outside of their own platforms. That makes it challenging data-wise for marketers to connect the rest of their media campaigns to what they are doing on those digital outlets, for example.

Beyond the walled garden issue, Weed once again highlighted what he dubs the "3Vs": Viewability, verification and value, saying that Unilever wanted only to buy ads that are 100% visible to consumers, and that he wanted third-party to track ad campaigns.

Plus, the marketing giant wants full digital ad transparency: i.e. it wants to know where its ads are running and how its digital budgets are being spent.

Weed said that while progress had been made on that front, there was still work to be done, particularly around issues of ad fraud and brand safety. Weed shared his own digital media report card, giving the issue of ad fraud a "C."

"...The digital media supply chain is still very murky, it still isn't where it should be," he said. "If we look at the report card on that, we're not quite there, but we are making progress."

He slammed those that offer up the excuse that digital advertising is still nascent.

"Is it that new now? It's been around for years," he said. "And certainly, a huge amount of money is being invested in it."

Prior to Advertising Week, Weed had raised the issue earlier this year at Cannes Lions, one of advertising's biggest annual gatherings. "We need to make sure the digital supply chain is less murky," he had said.