A method, system, computer program product, and related business methods for phased rollout of an upgraded version of a web-based business information system are described. URLs associated with client requests remain the same even where the target subscriber accounts have been upgraded. Client requests for both upgraded and non-upgraded accounts are received by a common set of web servers. Client requests representing external entry points are trapped, and the receiving web server accesses a login router database to determine whether the target subscriber account is upgraded or non-upgraded, and then transfers the request to an appropriately-versioned application server. Application server sets are mapped to database sets according to system version, allowing the upgraded system database schema to be substantially different than the non-upgraded database schema. An early adopter program business method leveraging the abilities of such web-based business information system is also described. Applications to environments other than phased rollout are described, such as URL-agnostic differentiation and routing of client requests according to class-of-service of the target subscribing account.