As publishers try to diversify their revenue, they're turning to consumer revenue strategies, including paywalls, memberships and commerce.

"This will be the year brands wonder what to do with the sheer volume of money they put into Facebook." The Facebook-Cambridge Analytica scandal, agency-client relationships and more were on the minds of marketing, publishing and agency executives at Advertising Week Europe.

After years of limiting the amount of inventory available to advertisers, Hulu has opened up more of it in the past year, as its subscriber base and the amount of time ad-supported viewers spend on the service have grown.

Publishers are getting creative to monetize their Facebook groups, using them to drive subscriptions, tapping members for market research and selling sponsorships to brands.

In a Digiday survey of media-buying executives, 42 percent said the hardest platform to advertise on is Snapchat. Subscribe to Digiday+ to learn why.

Marketers: Apply today to see if you qualify for a complimentary pass to the Digiday Programmatic Marketing Summit, taking place in New Orleans, where brands will share challenges and successes in managing their ad tech stacks.