Live's cashback program did save my money when buying a computer from HP.
Example:

Each time you click a Live Search cashback listing, you'll find great deals on
the product you chose. Your results will clearly list the cashback savings
you'll receive off the store price, and your final bottom-line price that
includes tax and shipping costs. Also look for this icon
when
you search for a product on Live Search to find great cashback deals.
See how it works from
http://search.live.com/cashback
Search
Search for cashback deals at Live
Search cashback. Each time you click a Live Search cashback listing, you'll
find great deals on the product you chose. Your results will clearly list the
cashback savings you'll receive off the store price, and your final bottom-line
price that includes tax and shipping costs. Also look for this icon
when
you search for a product on Live Search to find great cashback deals.
Shop
Compare and sort products by the bottom-line price. Click the best deal to go to
the store. Everything you buy during that store visit will be eligible for Live
Search cashback. On your first time using Live Search cashback, we will ask you
for an email address so we can tell you how to quickly set up your free cashback
account.
Save
Keep saving money each time you use Live Search cashback. Every time you make a
qualifying purchase, we'll send you an email to confirm your Live Search
cashback savings. Usually 60 days after your purchase (although this time period
may vary for some stores), and when your cashback account reaches a balance of
at least $5, you can claim your cold, hard cash.
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