Cory Doctorow on Boing Boing points to Wired Magazine and an excellent article on click-fraud from Charles C. Mann
How Click Fraud Could Swallow the Internet
"Pay-per-click advertising is big, big, big business. So are bogus hits on Internet ads. It's search giants against scam artists in an arms race that could crash the entire online economy."
Cory is summing up, better than I could do -:) :
"the practice of generating bogus clicks on Internet ads to either rack up affiliate fees or to rock up spurious charges against a competitor's account -- that explores the major sources of threats from click-fraud, the countermeasures arms-race against click-fraud, and the varying motives of fraud-fighters.
Other enterprising scammers manipulate the affiliate system by creating phony blogs - spam blogs, or splogs - that automatically generate content by continually copying bits from other Web sites, mixing in popular keywords, then signing up the resulting mélange as a Google or Yahoo! affiliate. By using software to link themselves repeatedly to well-known real blogs, splogs trick search engines into listing them high on their results list, thus generating traffic, which in turn generates ad clicks. When unsuspecting Internet searchers visit splogs, they end up clicking the ad links in a frustrated attempt to find some coherent text. Thousands of splogs exist, snarling the blogosphere - and the search engines that index it - in spam. Splogs are too profitable to be readily discouraged. According to RSS to Blog, a Brooklyn-based firm that sells automatic-blog software, sploggers can earn tens of thousands of dollars a month in PPC income, all without any human effort.
Probably the most worrisome emerging threat is ... " more
My idea about advertisers paying by clicks is very simple:
Click fraud will not go away (and increase, despite all protection efforts), until advertisers stop paying for clicks, but pay for traceable, verifiably value generated an integrated in their business process.
The efforts of search engines, portals and publisher can not win the game and should concentrate more on delivering this value - verifiably!