Buying ads on Twitter is ‘high-risk’ according to the world’s biggest ad agency

Twitter may be in big trouble when it comes to generating advertising revenue: GroupM, part of WPP, the world’s biggest ad company — and Twitter’s biggest spender — is reportedly telling its clients that buying ads on the platform is “high-risk,” according to

and Digiday. That makes it the third advertising juggernaut telling massive corporations that they might want to take their money elsewhere, after IPG and Omnicom…