Click Forensics is calling this the Internet marketing potential fraud behavior - "Bahama botnet" because initially it was redirecting traffic through 200,000 parked domains in the Bahamas, although it now is using sites in Amsterdam, the U.K. and Silicon Valley.
HTML tag Iframes can be very flexible too and is said to be potential source for the fraud - "Bahama botnet"; much less constrained than a "framed" page. They can be a great way to add an "update" section to a page without having to worry about the size of the new content.
Iframes place a smaller "box" containing another HTML document inside the larger main display. It's like having a smaller window inside the main window to display a separate source of information. Frames split an entire window into two or more sections. Frames run edge to edge rather than being a box placed somewhere inside.
Click fraud affects marketers who spend money on pay-per-click (PPC).
Sophisticated Botnet Causing a Surge in Click Fraud
Study: Half Of Ad Impressions, 95 Percent Of Clicks Fraudulent
NYtimes.com Ad Scam Linked to 'Bahama' Botnet
Click Fraud's New Asian Connection
Yahoo! Cozies Up To Its Click-Fraud Critics
Click Fraud Goes Viral
Google Defends Its Clicks
Note: First introduced by Microsoft Internet Explorer in 1997 and long only available in that browser, the iframe tag is now widely supported by visual browsers. Unlike an object element, an inline frame may be the "target" frame for links defined in other elements and it may be "selected" by a browser as the focus for printing, viewing HTML source etc.