It is being widely reported that Yahoo and eBay have formed a partnership.
To start, Yahoo will provide advertising on eBay's site, and eBay will provide PayPal payments to Yahoo (replacing Yahoo's defunct PayDirect feature). I am sure we can expect more announcements from this coupling in the future.
I would like to see a similar deal between Amazon and Microsoft. Amazon already switched its web searches from using Google to Microsoft. Danny Sullivan speculated that this deal probably already includes advertising on Amazon sites from the upcoming Microsoft adCenter.
Amazon also has a payments system similar to PayPal. Microsoft could build their own, but why bother when Amazon has one ready to go?
This would match the Yahoo/eBay deal, Microsoft running the advertising on Amazon properties and Amazon running payments on Microsoft properties. But, why stop there?
Amazon's excellent catalog and reviews could be integrated and featured in MSN Shopping, Windows Live Shopping, and Windows Live Products. Amazon's personalization technology could be deployed. Amazon's Alexa data could be surfaced in MSN Search results. Amazon's A9 could be repurposed within Microsoft Live Labs.
Amazon and Microsoft are neighbors, but have always been cold to each other. Perhaps it is time these two kissed and made up.