https://www.reuters.com/article/us-alphabet-google-assistant-ads-focus/when-it-comes-to-disclosing-sponsors-your-google-assistant-may-be-mute-idUSKCN1RD22D >On stage at an investor conference last month, Google's Chief Business Officer Philipp Schindler identified a vexing challenge for the company's most prized app: its virtual assistant.