Several companies, including AT&T and Nestle, are pulling advertisements from YouTube over concerns about inappropriate comments on videos of children.
A video from a popular YouTuber and a report from Wired showed that pedophiles have made unseemly comments on innocuous videos of kids. The comments reportedly included timestamps that showed where kids innocently bared body parts.
YouTube says it disabled comments on tens of millions of videos and deleted offending accounts and channels.
Nestle and Fortnite maker Epic Games say they paused ads on YouTube while the company works on the issue. AT&T says it has removed ads until YouTube can "protect our brand from offensive content of any kind."
YouTube has faced advertiser boycotts in the past, including a widespread boycott in early 2017. Since then YouTube has made efforts to be more transparent about how it deals with offensive comments and videos on its site.
But the latest flap shows how much of an ongoing problem offensive content continues to be, said eMarketer video analyst Paul Verna.
"When you think about the scope of that platform and what they're up against, it is really like a game of whack-a-mole to try to prevent these problems from happening," he said.
Still, because of the powerful advertising reach of YouTube's parent Google, brands are unlikely to stay away from YouTube for long, he said.
Digital ad spending in the U.S. is expected to grow 19 percent in 2019 to $129.34 billion this year, or 54 percent of estimated total U.S. ad spending, according to eMarketer, with Google and Facebook accounting for nearly 60 percent of that total.
"At the end of the day, there's a duopoly out there of Google and Facebook," for digital advertising, he said. "Any brand that doesn't play the game with either is potentially leaving a big marketing opportunity on the table."
