This is a very broad statement. Google's search ads revenue are growing just fine... Youtube is down though. WPP is seeing increased ad spend as well. Conclus

This is a very broad statement. Google's search ads revenue are growing just fine... Youtube is down though. WPP is seeing increased ad spend as well. Conclusion? Probably that apple has fucked facebook to such an extent that it's threatening their entire business. This isn't much to do with advertising in general.