South Africa, March 3 -- I've always felt that one of the biggest marketing cons of all time is digital advertising ... and now there's hard evidence. Uber has brought legal action against a number of its digital suppliers and agencies for fraud.

I listened to a fascinating podcast on Marketing Today, where Kevin Frisch, former head of performance marketing and customer relationship manager at Uber, revealed how he and his team uncovered a number of large-scale, deliberate frauds perpetrated on the company.

As a result, he cut $120m (R1.8bn) out of Uber's online ad budget of $150m. And, guess what? He noticed no difference in the recruitment of either drivers or riders, which is what he was using digital platforms for.

Maybe that's one...