Google Adsense has now enabled a referral (pay-per-lead) system whereby website publishers have the opportunity to earn from ads on their websites based on a referral system. Ads displayed can either be in image or text format and the publisher can specify the country and category ads to be displayed.
Earnings are based on how much the advertiser wishes to pay for each referral, and the target market/audience.
Would I earn more?
Not necessarily. This would depend on your target audience, as well as your content. Websites targetted at the USA, UK, Germany, Australia and other developed econoies, can expect to earn money since the ad inventory for these countries is huge and also, the buying power of folks in these countries are much higher.
The ideal thing would be for your to complement these pay-per-lead ads with your regular pay-per-click (PPC) or pay-per-impression (PPM) Google Adsense ad blocks. But again remember, too much ads on your webpages might not be much of a good thing.