Through my adsense account i can advertise the refferal campaigns where advertiser only gets paid per sale or per lead. When i go to my adwords account all i see is keyword-targeted and placement-targeted campaigns. How do i set up a pay per sale campaign?
Yes, it is possible. It's called pay per action (or conversion) and Google AdWords offers it. However, you must qualify to be able to use it. I think you need to average 300 conversions in a month. Does someone else know the exact number? Here's some information from Google AdWords Help.
I have seen a link show up on the Campaign Summary page for AdWords advertisers who get lots of conversions.
I'm a beta tester for it. I"m not sure if I'm supposed to say anything about how it works yet though...I'll check...