Advertisers and their agency partners using a smart bidding tool to run campaigns in Google Shopping that match to a preset return on ad spend (ROAS) were hit with cost per clicks (CPCs) and ad spend that were higher than usual for a few hours on December 6.
The issue was related to Shopping campaigns using ROAS settings.
ROAS bidding, an AdWords Smart Bidding strategy, allows advertisers to target ads to consumers based on a specific return on ad spend in AdWords. The bids are automatically optimized at the time of the auction.
Google identified and resolved the "engineering problem" on the same day, according to one search agency partner, who said marketers still need to keep a close eye on campaigns when they are using automated bidding policies because they are not infallible.
One advertiser wrote in a Google AdWords forum that he spent three times the company's "daily budget in a matter of hours on insane CPCs."
Another wrote in the forum "bid costs were over 500% of normal with no increase in ROAS."
Facebook, Google, Microsoft and others are pushing marketers to place more trust in machine learning and algorithms, but a glitch that surfaced last week in Google's Shopping Ad platform reminds marketers it's still a good idea to review all campaigns with their own eyes.
The search agency partner said one advertising client saw bids jump from 40 cents to $4 on a set of keywords. "We looked at others running smart bidding and they all saw a jump in CPCs during the same hour," per the agency rep. who was buying.
Advertisers had to pause their campaigns for 12 hours and go back to using manual triggers to run search ads.
Google will continue to reach out to advertisers that were impacted by the glitch, and plans to credit their accounts with the incorrect spend during the next few weeks.