Google woos online shoppers with cash

Google is once again running its back-to-school savings promotion that gives anyone a $5 to $10 discount on purchases made at one of the partnered stores using its Checkout service. Online shoppers must spend a certain amount at each store to get the discount, although unlike some previous promotions the discounts are not limited per user or per retailer, meaning you can come back multiple times to get the discount as long as you're hitting the minimum.

The much more interesting story is how well Microsoft's Live Search cash back program seems to have been going since its launch just a few months ago. Its varying percentage has kept online shoppers glued to Microsoft's tracking site. Meanwhile, deal hunting sites like Fatwallet and Slickdeals have had forum threads with post counts in the high hundreds detailing successes and failures using Microsoft's system at various retailers.

What's surprising is how much overlap there is between some of these stores that are vying for the attention. For instance, buying something on Drugstore.com using Google Checkout will only get you $5 back from Google, while Microsoft is currently taking 20 percent off your entire order--a number that could change rapidly depending on the retailer's agreement with Microsoft. In either case, the winners are the savvy consumers who have managed to work the system to get big discounts while the two companies scramble to get the most attention.