One embodiment of the present invention provides apparatus and methods for queuing access by large numbers of Internet or other network-based users to networked systems and resources with limited capacity. In one example embodiment, a queuing system provides user access to network resources, such as that of a ticketing system. A ticket queue queues a request received from a client system. A request processing module causes the client system to repeatedly transmit messages to the system during a first period, and in response to determining that the client system has ceased transmitting messages during the first period, the request is remove from the queue and/or cause the request goes unfulfilled.