You have heard about fraud and online advertising. You may have seen the Wall Street Journal video "Porn Sites Scam Advertisers", or even read the story at today's Wall Street Journal about "Off Screen, Porn Sites Trick Advertisers" (Hint: to avoid the WSJ paywall, search the title of the article through Google News and click from there, to read the full article).
Since I am intimately familiar with the story covered by WSJ (i.e., I was part of the team at AdSafe that uncovered it), I thought it would be also good to cover the technical aspects in more detail, uncovering the way in which this advertising fraud scheme operated.
It is long but (I think) interesting. It is a story of a one-man-making-a-million-dollar-per-month fraud scheme. It shows how a moderately sophisticated advertising fraud scheme can generate very significant monetary benefits for the fraudster: Profits of millions of dollars per year.
Waoh, just waoh. O.o