From the WPP Stream in Ojai, California Cheddar's CEO Jon Steinberg speaks with WPP CEO Sir Martin Sorrell about the future of advertising.

The ad exec says clients want platforms like Snap and Pinterest to succeed. With the duopoly of Google and Facebook dominating the industry, with 75 percent of digital advertising and 30 percent of the entire ad market, his clients want control to be more distributed.

While Sorrell has seen Google as a "frenemy" in the past, he says he now sees the technology giant as a "flexible friend," because it's become more responsive to concerns. One of the reasons for Google's shift, Sorrell says, is the rise of companies like Amazon which provide an existential threat to the search and advertising model.

There's also been a lot of talk about how the rise of artificial intelligence may impact the American workforce. Sorrell says technology could be a net destroyer of jobs, and he expects that to become an increasingly critical political issue.

Last month, WPP cut its growth forecast for the third time this year. In the latest quarterly, revenue grew 0.8 percent to $4.78 billion. Sorrell says, "It's been very tough," and he's looking to see how things pan out next year. On the future of advertising, Sorrell says investment in innovation and branding is critically important.