Part of a recent Mercedes-Benz online advertising campaign was viewed more often by automated computer programmes than by human beings, according to documents seen by the Financial Times.
The ads were inadvertently placed on to fraudulent websites by Rocket Fuel, a Nasdaq-listed ad technology company that went public last September with a market capitalisation of nearly $1bn.
The incident will intensify concerns about the prevalence of fraud in the fast-growing online advertising market, which expanded 15 per cent last year to $120bn.
In Mercedes-Benz’s case, the suspicious traffic was discovered in an investigation for the German carmaker by Telemetry, a UK company that specialises in detecting ad fraud.
In a sample of 365,000 ad impressions brokered by Rocket Fuel over three weeks, Telemetry found that 57 per cent were “viewed” by automated computer programs rather than real people.
Mercedes said that over the whole of its campaign, the proportion of questionable impressions was less than 6 per cent, and that Rocket Fuel “refunded us for the suspect impressions”. The carmaker added that it and its US advertising agency, Merkley & Partners, which is part of Omnicom Group, have continued to work with Rocket Fuel.
There is no suggestion that Rocket Fuel, which acts as an intermediary between advertisers and online publishers, was aware that it was delivering its client’s ads to fraudsters. The company buys ad inventory via ad exchanges, which are in turn plugged in to thousands of publishers.
However the findings raise questions about Rocket Fuel’s assertions on its website that it “makes sure the ‘bad actors’ always leave empty-handed”.
Rocket Fuel played down Telemetry’s report, saying it was not sure that the figures were “100 per cent correct”. It said the findings came from a small sample and did not represent the type of traffic that normally passes through its systems.
To identify and block suspicious activity, Rocket Fuel uses a combination of its own technology and partnerships with third parties such as Double Verify and Integral Ad Science.
Rocket Fuel said that in February, it identified and rejected 500bn bid requests from online publishers because of inventory quality concerns.
Fraudsters are coming up with increasingly sophisticated ways to deceive online advertisers, using software that mimics the behaviour of a real person browsing the web.
Telemetry detected the bots by identifying anomalies in traffic to the ads. Virtually all of the suspect traffic came from five small internet service providers. And the computers “viewing” the ads used Linux, an operating system rarely used on desktops, though they attempted to disguise this by simulating popular web browsers that only work on Windows or Macs.
Telemetry said it had traced the ownership of the bot network to two people in the UK, who directed the bots to websites they owned, thereby making money from the ad sales. The websites have since disappeared.