Live Search cashback hasn’t publically shared many numbers that we’ve seen, so these numbers kind of jumped off the screen when we noticed them in a Tweet.  Clicking through to the article, the numbers weren’t attributed, but it wasn’t too hard to track them back to a Microsoft Careers post, advertising for an SDET in “Subscription and Commerce”.  From the Codename Windows post (taken from the Careers job listing):

Cashback is changing the way online shopping works - it is the future of online shopping: users search for a product, buy it, receive CashBack from Microsoft subsidized by the merchants, creating a win-win cycle where merchants are encouraged to increase the CashBack to attract more users, benefiting both parties. We have launched version 1.0 of CashBack and we get more than 5,000,000 views a day and 10,000 purchases every day - and we’re exponentially growing!

Live Search cashback has integrated into Live Search Products (which incidentally recently shut down the Live Search Product Upload beta).  The Careers post goes on to clarify a bit more just where everything sits:

We’re part of the CSAT (Commerce Search Advertising Transactions) which in addition to the Product Search owns the transactions platform for several online services across the company (such as Xbox Live, Zune, AdCenter, Office Live, MSN, OneCare, CRM Live and Windows Live), providing the payments infrastructure used by all these services.

Just imagine what cashback could do with a solidified brand and some advertising push behind it.