It's stupid that they killed Bing cashback.
Basically, a few years ago, there was a site called jellyfish.com. They figured that they could use affiliate linking to make a profit, take a cut off the top, and then give a check back to the consumer for some of the affiliate money. They also had cool "Smack Shows" where they'd have an unknown quantity of an item, and you'd watch the discount rise on the item. It was a game of chicken since you wouldn't know when there was only one left (or if there was more than one), so if you waited too long you'd forego any form of discount altogether. I almost got a PRS-500 in 2006 for $150...
Microsoft liked the concept and thought it would make Bing popular, so they implemented it.
Microsoft markets the concept, but not the engine. So Microsoft tries to increase usage through cashback promos where they pay out more cashback then they take in (MS did the same with the Xbox, and while that division is still deep in the hole, it has made a consistent quarterly profit for a couple years). The result is sites like SlickDeals and Fatwallet using it heavily, but consumers not even knowing about it.
So Microsoft moves the extra cashback links into ads within the Bing search (if you go to bing.com/cashback you may see 3% for Tiger Direct, but if you search "LCD TV" on bing instead you get 15%). Neat concept, but it just lead to people keyword scrapung regularly for extra cashback links.
Microsoft could have saved the program by marketing it better (a TV commercial where someone is enjoying their laptop, or watching their new plasma, and a guy from Microsoft shows up and hands them some cash. Simple, effective, memorable.) and stopping encouraging SlickDeals by making unprofitable promos (e.x. 30% off eBay and HP) that people would watch deal sites for and not use the search engine at all.