People count up the faults of those who keep them waiting.
Users of modern websites have lofty expectations when it comes to application responsiveness—most likely they will expect behavior and speed similar to that of desktop applications. Proper user experience guidelines would dictate that no HTTP request/response cycle should take more than a second to execute. However, there will be actions that arise that simply cannot achieve this time constraint.
Tasks of this nature can range from simple, long running tasks due to network latency to more complex tasks that require heavy processing on the server. Examples of these actions could be sending an email or processing video, respectively. In ...