Why Fraudulent Ad Networks Continue to Thrive

Harvard Business Review

To see how the bad guys operate, we follow the money trail. In the display advertising world, advertisers pay by thousands of ad impressions, denoted CPM (cost per thousand). At an average CPM of $1, this budget buys 100 million ad impressions. Not long ago, these bots operated from computers taken over by malware but the fraudsters now prefer to generate fake browsing sessions in the cloud, because it’s more efficient.