receiveMessageWaitTimeSeconds

Specifies the duration, in seconds, that the ReceiveMessage action call waits until a message is in the queue in order to include it in the response, rather than returning an empty response if a message isn't yet available. You can specify an integer from 1 to 20. Short polling is used as the default or when you specify 0 for this property. For more information, see Consuming messages using long polling in the Developer Guide.