MBD revenue increased primarily reflecting sales of the 2010 Microsoft Office system. Business revenue increased $326 million or 8%, primarily reflecting growth in multi-year volume licensing revenue, licensing of the 2010 Microsoft Office system to transactional business customers, and a 17% increase in Microsoft Dynamics revenue. Consumer revenue increased $75 million or 7% due mainly to strong sales of the 2010 Microsoft Office system.
MBD revenue for the three months ended September 30, 2011 included a favorable foreign currency impact of $206 million.
MBD operating income increased due to revenue growth, offset in part by higher operating expenses. Cost of revenue increased $97 million or 27%, primarily driven by higher online operation and support costs. Sales and marketing increased $76 million or 9%, due mainly to increased corporate marketing activities and higher fees paid to third party enterprise software advisors.