Originally Posted by Quickdraw

This is only the tip of things but it is a good example of how traffic is being diverted from many places.

The following comes from 1 click on an infected machine. Everything in the quote all took place in about a second.
Notice that after clicking an ad on the Google results, it takes the user through the Google ad to the intended advertiser. It is then redirected so fast that most people won't even realize they even went to the intended site.

So, the advertisers on Google(and the other engines) are getting hit by a PPC charge, for traffic that really doesn't even make it to their site, but for a millisecond.

The traffic that is redirected is sent to various smaller PPC engines, through multiple redirects. The user finally lands at a, non-affiliated, top paying advertiser for these various PPC engines and the terms used. In this case the term was 'tomato seeds'.

this is happening for all keywords and all niches, mainstream and adult.