SAN FRANCISCO:- A Google training exercise that went wrong meant a dummy advert was placed on a “huge number” of webpages and apps, the Financial Times has reported. The mistake meant a blank yellow rectangle was active on the sites and apps for about 45 minutes on 4 December, it said. The ad was only visible to people in the US and Australia. The mistake happened when trainees were being shown how to use Google’s in-house ad placing system. The ad was sent out because one trainee “went further than intended” and submitted a live order into the advert buying system.–GN

The advert was placed at a far higher rate of return than any other ad and was routed through several third-party exchanges, so it reached a wide audience.