from www.adage.com – Porn generates a huge amount of online traffic. But did you know it also generates quite a bit of ad revenue? None of it is direct, of course; mainstream advertisers aren’t buying adult sites, and you will never see a Chrysler or a Kraft ad there. But their ad dollars could find their way back to adult sites through a number of click-laundering scams commonplace to the web today.

One of the most common: adult sites that automatically generate millions of fake impressions that are sold through middlemen to publishers, and ultimately to advertisers. A ComScore audit found some adult sites generating as many as 200 false impressions in a five-minute period, many of which end up reported as legitimate impressions to advertisers.

Here’s what happens:
1. When a surfer visits a porn site, a tiny 1×1 javascript pixel is launched. Invisible to the user, it looks like a fully-loaded web page to the internet, including ad calls and analytics beacons.

2. The javascript in that pixel redirects the traffic to the first in a series of middlemen like this fictional example, click.trafficprovider.com, that obfuscate its origin.

3. After several hops to different middlemen, the traffic ends up in what looks like a benign site created as part of the scam, which creates an impression that can be sold.

4. A pay-per-click advertiser then buys the traffic from the middlemen intending to turn around and sell it to a publisher. (Money from this transaction flows back through the middlemen and ultimately, the porn site.)

5. The publisher buys the referral traffic, a common practice to boost unique visitors and page views they can sell to advertisers.

6. The publisher’s ad server serves the ad.

7. An unwitting advertiser ends up buying the impression oblivious to the fact that it was generated fraudulently.