I'm surprised there hasn't been more press coverage of this aspect:
As part of the program, Microsoft is also unveiling a new business model that allows search marketers to pay for ads only when people buy a product, rather than when they simply click on an ad.
Microsoft said this so-called cost-per-action model would give advertisers more precise returns on their marketing budgets. Google already offers a program that allows advertisers to tailor their bids on keywords based on the number of actions, or conversions, they get.
Microsoft also said that it had integrated Farecast, a travel Web site that Microsoft acquired in April, into Live Search cashback. The Live Search cashback service was built on technology developed by Jellyfish, a start-up that Microsoft acquired in 2007.