They buy traffic from Google Adwords and redirect it to :
pricedepot.net
lowerprices.us
smartprices.us
dealhunter.us
bestdiscounts.us
applianceprices.net
shopsave.us
They got paid through CPC ads as far as I can tell, and the business behing is HUGE : ~60 M$/year
Have you heard of them?
"In 2010, we had revenues of more than $60m"
Source : http://ma.rcus.co.uk/2011/08/29/clicksco-group-2/
the problem is get the ad approve in adwords i think
Have seen their ads hundreds of times, never looked too far into it though
Just your typical doorway site with adsense ads that leads the customer offsite to make a purchase that google loves to tell you not run in Adwords.