Revenue recognition . The Company's operating revenues are comprised principally of service revenues, data processing revenues, international transaction revenues and other revenues, reduced by costs incurred under client incentives arrangements. The Company recognizes revenue when the price is fixed or determinable, persuasive evidence of an arrangement exists, the service is performed and collectability of the resulting receivable is reasonably assured. Service revenues consist primarily of revenues earned for providing clients with a supported global business infrastructure and for services which support the various product platforms that enable clients to deliver Visa products and payment services. Current quarter service revenues are primarily assessed using a calculation of pricing applied to the prior quarter's payments volume. The Company also earns revenues from assessments designed to support ongoing acceptance and volume growth initiatives, which are recognized in the same period the related volume is transacted. Data processing revenues represent revenues earned for authorization, clearing, settlement, transaction processing services, network access and other maintenance and support services that facilitate transaction and information processing among the Company's clients globally and Visa Europe. Data processing revenues are also earned for transactions processed by CyberSource's online payment gateway and PlaySpan's virtual goods payment platform. Data processing revenues are recognized in the same period the related transactions occur or services are rendered. International transaction revenues are earned for processing cross-border transactions, and currency conversion activities. Cross-border transactions arise when the cardholder's issuer country is different from the merchant's country. International transaction revenues are generally driven by cross-border payments and cash volume. Other revenues consist primarily of license fees for use of the Visa brand, revenues earned from Visa Europe in