Methods and apparatus provide for: assigning each of a plurality of requesters to a respective one of a plurality of requester groups; receiving tokens from a plurality of resources, where each token is an exchange medium for permitting one of the requesters having the token to access an associated one of the resources for a period of time; receiving requests for the tokens from one or more of the requesters; allocating the tokens to at least one of the respective requester groups and the requesters thereof based on token allocation criteria; and dynamically re-assigning one or more of the requesters among the requester groups based on feedback information concerning at least some prior token allocations.