For new or existing members, Bing Rewards offers 400 Microsoft Points for use on the Xbox LIVE Marketplace for 300 Bing Credits. (Click here and login or register; it's free.) That's a savings of 200 Bing Credits and one of the best deals we've seen for 400 Microsoft Points. Deal ends October 23.
Bing Rewards is a free service that allows you to earn credits redeemable for rewards. You can earn Bing Credits by conducting searches on Bing or trying out Bing services. Click here to view current opportunities to earn credits. Complete details can be found here.