Joseph Weisenthal, writing at paidcontent.org, notes that a similar attempt has been made by Google with its Checkout program.

"Cash back, of course, is used in all kinds of industries. Even Google (NSDQ: GOOG) has tried a variation on this model for its PayPal-competitor Google Checkout. Will it work? Getting users to switch their search behavior is tough, and it will be a challenge getting it up to scale. If we lived in an economist’s dream world, where every individual acted perfectly rational, then it might have a better chance."

CNET's Charles Cooper, acknowledging Microsoft's lagging position in search, also thinks it can't hurt.

"But truth be told, it's not the worst idea. What's the harm in giving it a shot? In a recession -- or whatever you want to call the current economic malaise in the United States -- consumers are open to bribes (oh, I forgot: rebates). So why not see if this strikes the people's fancy? But this is only a holding action. The reason more people use Google's search is the user experience. It works better, so they keep returning. Microsoft CEO Steve Ballmer knows this. That's why he still thinks making a move for some of Yahoo's assets makes sense. He's anxious about staying pat with Microsoft's current search hand and wants to fix things, either through developing technology internally or buying it on the open market.

"No way this is the final word."

Barry Schwartz at SearchEngineLand writes about using the cashback service to search for an umbrella.

"Microsoft is telling me that I will be getting back $4.45 on my purchase of this umbrella. Interesting. I continue on with my purchase to inquire.

"The next screen I click on tells me to enter my email address and to expect an email from Microsoft on how I can claim my cashback reward. It specifically explains I will not see my discount on the store, but that I will get an email from Microsoft with the discount information. ...

"Overall, the process is fairly easy for me personally. I totally can see an average person having a lot of difficulty in trusting they will get back the money and also in setting up their cashback account with Windows Live. Other then that, I personally feel this won't do much, in the long term, to improve Microsoft's search share."