Adweek: Even as WPP has recently invested more in digital players like BuzzFeed, Adobe and Snapchat, CEO Martin Sorrell said online media still lacks accurate measurement tools, singling out Facebook and its ongoing viewability issues. Facebook, in particular, has come under heat in recent months from some advertisers who do not want to pay for videos that are viewed for only three seconds as someone scrolls through a newsfeed. “Three seconds — and 50 percent of video online not listened to with sound — is ludicrous,” Sorrell said.