PROS Holdings, Inc. (PROS) is a provider of pricing and revenue optimization software. The Company's PROS Pricing Solution Suite is a set of integrated software products that addresses three areas to implement and execute an effective pricing solution: pricing analytics, pricing execution and pricing optimization. These software products support pricing decisions through the aggregation and analysis of enterprise application data, transactional data and market information. PROS also provides professional services to configure the software products to meet the specific pricing needs of customers, including those who process large volumes of individually priced business-to-consumer and business-to-business transactions on a daily basis. Its software products are offered to the manufacturing, distribution, services, hotel and cruise, and airline industries. During the year ended December 31, 2007, approximately 63% of the its total revenue came from customers outside the United States.